UNITED STATES                                  
                       SECURITIES AND EXCHANGE COMMISSION                       
                             Washington, D.C. 20549                             


                                  SCHEDULE 13G                                  
                   Under the Securities Exchange Act of 1934                    
                               (Amendment No. 4)*                               


                                  Exagen, Inc.                                  
                                (Name of Issuer)                                
                    Common Stock, par value $0.001 per share                    
                         (Title of Class of Securities)                         
                                   30068X103                                    
                                 (CUSIP Number)                                 
                               December 31, 2023                                
            (Date of Event Which Requires Filing of this statement)             


Check theappropriate box to designate the rule pursuant to which this Schedule 
is filed:
Rule
13d-1(b)
Rule
13d-1(c)
Rule
13d-1(d)


* The remainder of this cover page shall be filled out for a reporting  
  person's initial filing on this formwith respect to the subject class 
  of securities, and for any subsequent amendment containing information
  which would alter the disclosures provided in a prior cover page.     

The information required in the remainder of this cover page shall not be 
deemed to be "filed" for purposes of Section 18 of the SecuritiesExchange Act 
of 1934 ("Act") or otherwise subject to the liabilities of that section of the 
Act but shall be subject to all other provisions of the Act (however, see the 
Notes).




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CUSIP No: 30068X103    Page 2 of 12



                                                                           
(1)  NAMES OF REPORTING PERSONS                                            
                                                                           
     Tullis-Dickerson Capital Focus III, L.P.                              
(2)  CHECK THE APPROPRIATE BOX IF AMEMBER OF A GROUP (SEE INSTRUCTIONS)    
     (a)(b)                                                                
                                                                           
(3)  SEC USE ONLY                                                          
                                                                           
(4)  CITIZENSHIP OR PLACE OFORGANIZATION                                   
                                                                           
     Delaware, United States ofAmerica                                     


                                                                       
       NUMBER OF                                 (5)  SOLE VOTING POWER
 SHARES 	BENEFICIALLY	                                                 
       OWNED BY                                       0                
         EACH                                                          
       REPORTING                                                       
        PERSON                                                         
         WITH                                                          
        (6)             SHARED VOTING POWER     
                                                
                        1,112,357               
        (7)             SOLE DISPOSITIVE POWER  
                                                
                        0                       
        (8)             SHARED DISPOSITIVE POWER
                                                
                        1,112,357               


                                                                                                
(9)   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                              
                                                                                                
      1,112,357                                                                                 
(10)  CHECK BOX IF THE AGGREGATEAMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)    
                                                                                                
                                                                                                
(11)  PERCENT OF CLASS REPRESENTED BYAMOUNT IN ROW (9)                                          
                                                                                                
      6.5%                                                                                      
(12)  TYPE OF REPORTING PERSON (SEEINSTRUCTIONS)                                                
                                                                                                
      PN                                                                                        


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CUSIP No: 30068X103    Page 3 of 12



                                                                           
(1)  NAMES OF REPORTING PERSONS                                            
                                                                           
     Tullis-Dickerson Partners III, L.L.C.                                 
(2)  CHECK THE APPROPRIATE BOX IF AMEMBER OF A GROUP (SEE INSTRUCTIONS)    
     (a)(b)                                                                
                                                                           
(3)  SEC USE ONLY                                                          
                                                                           
(4)  CITIZENSHIP OR PLACE OFORGANIZATION                                   
                                                                           
     Delaware, United States ofAmerica                                     


                                                                       
       NUMBER OF                                 (5)  SOLE VOTING POWER
 SHARES 	BENEFICIALLY	                                                 
       OWNED BY                                       0                
         EACH                                                          
       REPORTING                                                       
        PERSON                                                         
         WITH                                                          
        (6)             SHARED VOTING POWER     
                                                
                        1,112,357               
        (7)             SOLE DISPOSITIVE POWER  
                                                
                        0                       
        (8)             SHARED DISPOSITIVE POWER
                                                
                        1,112,357               


                                                                                                
(9)   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                              
                                                                                                
      1,112,357                                                                                 
(10)  CHECK BOX IF THE AGGREGATEAMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)    
                                                                                                
                                                                                                
(11)  PERCENT OF CLASS REPRESENTED BYAMOUNT IN ROW (9)                                          
                                                                                                
      6.5%                                                                                      
(12)  TYPE OF REPORTING PERSON (SEEINSTRUCTIONS)                                                
                                                                                                
      OO (Limited Liability Company)                                                            


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CUSIP No: 30068X103    Page 4 of 12



                                                                           
(1)  NAMES OF REPORTING PERSONS                                            
                                                                           
     Tullis Growth Fund, L.P.                                              
(2)  CHECK THE APPROPRIATE BOX IF AMEMBER OF A GROUP (SEE INSTRUCTIONS)    
     (a)(b)                                                                
                                                                           
(3)  SEC USE ONLY                                                          
                                                                           
(4)  CITIZENSHIP OR PLACE OFORGANIZATION                                   
                                                                           
     Delaware, United States ofAmerica                                     


                                                                       
       NUMBER OF                                 (5)  SOLE VOTING POWER
 SHARES 	BENEFICIALLY	                                                 
       OWNED BY                                       0                
         EACH                                                          
       REPORTING                                                       
        PERSON                                                         
         WITH                                                          
        (6)             SHARED VOTING POWER     
                                                
                        587,843                 
        (7)             SOLE DISPOSITIVE POWER  
                                                
                        0                       
        (8)             SHARED DISPOSITIVE POWER
                                                
                        587,843                 


                                                                                                
(9)   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                              
                                                                                                
      587,843                                                                                   
(10)  CHECK BOX IF THE AGGREGATEAMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)    
                                                                                                
                                                                                                
(11)  PERCENT OF CLASS REPRESENTED BYAMOUNT IN ROW (9)                                          
                                                                                                
      3.4%                                                                                      
(12)  TYPE OF REPORTING PERSON (SEEINSTRUCTIONS)                                                
                                                                                                
      PN                                                                                        


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CUSIP No: 30068X103    Page 5 of 12



                                                                                                   
(1)      NAMES OF REPORTING PERSONS                                                                
                                                                                                   
         Tullis-Growth Partners, L.L.C.                                                            
(2)      CHECK THE APPROPRIATE BOX IF AMEMBER OF A GROUP (SEE INSTRUCTIONS)                        
         (a)(b)                                                                                    
                                                                                                   
(3)      SEC USE ONLY                                                                              
                                                                                                   
(4)      CITIZENSHIP OR PLACE OFORGANIZATION                                                       
                                                                                                   
         Delaware, United States of America                                                        
       NUMBER OF                                  (5)                             SOLE VOTING POWER
 SHARES 	BENEFICIALLY	                                                                             
        OWNED BY                                                                  0                
          EACH                                                                                     
       REPORTING                                                                                   
         PERSON                                                                                    
          WITH                                                                                     
     (6)                 SHARED VOTING POWER     
                                                 
                         587,843                 
     (7)                 SOLE DISPOSITIVE POWER  
                                                 
                         0                       
     (8)                 SHARED DISPOSITIVE POWER
                                                 
                         587,843                 
(9)      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                              
                                                                                                   
         587,843                                                                                   
(10)     CHECK BOX IF THE AGGREGATEAMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)    
                                                                                                   
                                                                                                   
(11)     PERCENT OF CLASS REPRESENTED BYAMOUNT IN ROW (9)                                          
                                                                                                   
         3.4%                                                                                      
(12)     TYPE OF REPORTING PERSON (SEEINSTRUCTIONS)                                                
                                                                                                   
         OO (Limited Liability Company)                                                            



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CUSIP No: 30068X103    Page 6 of 12



                                                                                                   
(1)      NAMES OF REPORTING PERSONS                                                                
                                                                                                   
         Tullis Growth Fund II, L.P.                                                               
(2)      CHECK THE APPROPRIATE BOX IF AMEMBER OF A GROUP (SEE INSTRUCTIONS)                        
         (a)(b)                                                                                    
                                                                                                   
(3)      SEC USE ONLY                                                                              
                                                                                                   
(4)      CITIZENSHIP OR PLACE OFORGANIZATION                                                       
                                                                                                   
         Delaware, United States of America                                                        
       NUMBER OF                                  (5)                             SOLE VOTING POWER
 SHARES 	BENEFICIALLY	                                                                             
        OWNED BY                                                                  0                
          EACH                                                                                     
       REPORTING                                                                                   
         PERSON                                                                                    
          WITH                                                                                     
     (6)                 SHARED VOTING POWER     
                                                 
                         105,620                 
     (7)                 SOLE DISPOSITIVE POWER  
                                                 
                         0                       
     (8)                 SHARED DISPOSITIVE POWER
                                                 
                         105,620                 
(9)      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                              
                                                                                                   
         105,620                                                                                   
(10)     CHECK BOX IF THE AGGREGATEAMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)    
                                                                                                   
                                                                                                   
(11)     PERCENT OF CLASS REPRESENTED BYAMOUNT IN ROW (9)                                          
                                                                                                   
         0.6%                                                                                      
(12)     TYPE OF REPORTING PERSON (SEEINSTRUCTIONS)                                                
                                                                                                   
         PN                                                                                        


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CUSIP No: 30068X103    Page 7 of 12



                                                                                                   
(1)      NAMES OF REPORTING PERSONS                                                                
                                                                                                   
         Tullis-Growth Partners II, L.L.C.                                                         
(2)      CHECK THE APPROPRIATE BOX IF AMEMBER OF A GROUP (SEE INSTRUCTIONS)                        
         (a)(b)                                                                                    
                                                                                                   
(3)      SEC USE ONLY                                                                              
                                                                                                   
(4)      CITIZENSHIP OR PLACE OFORGANIZATION                                                       
                                                                                                   
         Delaware, United States of America                                                        
       NUMBER OF                                  (5)                             SOLE VOTING POWER
 SHARES 	BENEFICIALLY	                                                                             
        OWNED BY                                                                  0                
          EACH                                                                                     
       REPORTING                                                                                   
         PERSON                                                                                    
          WITH                                                                                     
     (6)                 SHARED VOTING POWER     
                                                 
                         105,620                 
     (7)                 SOLE DISPOSITIVE POWER  
                                                 
                         0                       
     (8)                 SHARED DISPOSITIVE POWER
                                                 
                         105,620                 
(9)      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                              
                                                                                                   
         105,620                                                                                   
(10)     CHECK BOX IF THE AGGREGATEAMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)    
                                                                                                   
                                                                                                   
(11)     PERCENT OF CLASS REPRESENTED BYAMOUNT IN ROW (9)                                          
                                                                                                   
         0.6 %                                                                                     
(12)     TYPE OF REPORTING PERSON (SEEINSTRUCTIONS)                                                
                                                                                                   
         OO (Limited Liability Company)                                                            



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CUSIP No: 30068X103    Page 8 of 12



                                                                                                   
(1)      NAMES OF REPORTING PERSONS                                                                
                                                                                                   
         James L.L. Tullis                                                                         
(2)      CHECK THE APPROPRIATE BOX IF AMEMBER OF A GROUP (SEE INSTRUCTIONS)                        
         (a)(b)                                                                                    
                                                                                                   
(3)      SEC USE ONLY                                                                              
                                                                                                   
(4)      CITIZENSHIP OR PLACE OFORGANIZATION                                                       
                                                                                                   
         United States of America                                                                  
       NUMBER OF                                  (5)                             SOLE VOTING POWER
 SHARES 	BENEFICIALLY	                                                                             
        OWNED BY                                                                  61,296           
          EACH                                                                                     
       REPORTING                                                                                   
         PERSON                                                                                    
          WITH                                                                                     
     (6)                 SHARED VOTING POWER     
                                                 
                         1,805,820               
     (7)                 SOLE DISPOSITIVE POWER  
                                                 
                         61,296                  
     (8)                 SHARED DISPOSITIVE POWER
                                                 
                         1,805,820               
(9)      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                              
                                                                                                   
         1,867,116                                                                                 
(10)     CHECK BOX IF THE AGGREGATEAMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)    
                                                                                                   
                                                                                                   
(11)     PERCENT OF CLASS REPRESENTED BYAMOUNT IN ROW (9)                                          
                                                                                                   
         10.7%                                                                                     
(12)     TYPE OF REPORTING PERSON (SEEINSTRUCTIONS)                                                
                                                                                                   
         IN                                                                                        



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CUSIP No: 30068X103    Page 9 of 12



Item	1. Security and Issuer.



(a) Name of Issuer:

Exagen, Inc.


(b) Address of Issuer:

1261 Liberty Way
Vista, CA 92081


Item	2. Identity and Background.



(a) Name of Person Filing:

This statement is being filed on behalf of each of the following persons 
(each, a "Reporting Person" and collectively, the"Reporting Persons"):


i.. Tullis-Dickerson Capital Focus III, L.P. ("
    TD Capital Focus                           
    ")                                         



ii. Tullis-Dickerson Partners III, L.L.C., the general partner of TD Capital Focus



iii. Tullis Growth Fund, L.P. ("
     Tullis Growth Fund         
     ")                         



iv. Tullis-Growth Partners, L.L.C., the general partner of Tullis Growth Fund



v. Tullis Growth Fund II, L.P. ("
   Tullis Growth Fund II         
   ")                            



vi. Tullis-Growth Partners II, L.L.C., the general partner of Tullis Growth Fund II



vii. James L.L. Tullis as majority member of Tullis-Dickerson Partners III, L.L.C.,           
     Tullis-Growth Partners, L.L.C.,and Tullis-Growth Partners II, L.L.C. (collectively, the "
     General Partners                                                                         
     "), and in his individual capacity                                                       



(b) Address of Principal Business Office or, if none, Residence:

The address of the principal business office of each of the reporting persons 
is:
11770 US Highway One, Suite 503, Palm Beach Gardens, FL 33408


(c) Citizenship or Place of Organization:

James L. L. Tullis is a citizen of the United States and each of the remaining 
Reporting Persons are organized under the laws of the state ofDelaware.


(d) Title of Class of Securities:

Common Stock, par value $0.001 per share


(e) CUSIP Number:

30068X103
Item	3.
Not applicable.

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CUSIP No: 30068X103    Page 10 of 12



Item	4. Ownership



(a) Amount Beneficially Owned:

See row 9 of the cover page of each Reporting Person.
As of December 31, 2023, the general partner of TD Capital Focus, Tullis 
Dickerson Partners III, L.L.C. may be deemed to share beneficialownership of 
1,112,357 shares of the Issuer's Common Stock held of record by TD Capital 
Focus. As the general partner of Tullis Growth Fund, Tullis-Growth Partners, 
L.L.C. may be deemed to share beneficial ownership of 587,843 shares of 
theIssuer's Common Stock held of record by Tullis Growth Fund. As the general 
partner of Tullis Growth Fund II, Tullis-Growth Partners II, LLC may be deemed 
to share beneficial ownership of 105,620 shares of the Issuer's Common Stock 
held ofrecord by Tullis Growth Fund II. James L.L. Tullis, in his individual 
capacity, is the record holder of 61,296 shares of the Issuer's Common Stock, 
including 39,948 shares of common stock underlying immediately exercisable 
stock options, and isthe majority member of each of the General Partners, and 
as a result, may be deemed to beneficially own the securities held of record 
by TD Capital Focus, Tullis Growth Fund, and Tullis Growth Fund II. Mr. Tullis 
and the General Partnersdisclaim beneficial ownership of any securities held 
of record by TD Capital Focus, Tullis Growth Fund, and Tullis Growth Fund II 
except to the extent of any proportionate pecuniary interest therein.
Pursuant to Rule
13d-4
of the Securities Exchange Act of 1934, as amended (the "ExchangeAct"), the 
Reporting Persons declare that filing this Schedule 13G shall not be construed 
as an admission that any such person is, for the purposes of Section 13(d) 
and/or Section 13(g) of the Exchange Act, the beneficial owner of anyCommon 
Stock covered by this Schedule 13G except to the extent of such person's 
direct ownership of such Common Stock, and except to the extent of such direct 
ownership, such beneficial ownership is expressly disclaimed by each 
ReportingPerson.


(b) Percent of Class:



i. TD Capital Focus: 6.5%



ii. Tullis-Dickerson Partners III, L.L.C.: 6.5%



iii. Tullis Growth Fund: 3.4%



iv. Tullis-Growth Partners, L.L.C.: 3.4%



v. Tullis Growth Fund II: 0.6%



vi. Tullis-Growth Partners II, L.L.C.: 0.6%



vii. James L. L. Tullis: 10.7%

Percentage calculated based on 17,045,827 shares of Common Stock outstanding 
as of November 10, 2023, as reported in the issuer'sQuarterly Report on Form
10-Q
for the quarter ended September 30, 2023.


(c) Number of shares as to which such person has:



(i) Sole power to vote or to direct the vote:

See row 5 of the cover page of each Reporting Person.


(ii) Shared power to vote or to direct the vote:

See row 6 of the cover page of each Reporting Person


(iii) Sole power to dispose or to direct the disposition of:

See row 7 of the cover page of each Reporting Person.


(iv) Shared power to dispose or to direct the disposition of:

See row 8 of the cover page of each Reporting Person.

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CUSIP No: 30068X103    Page 11 of 12



Item	5. Ownership of Five Percent or Less of a Class

Not applicable.


Item	6. Ownership of More than Five Percent on Behalf of Another Person

Not applicable.


Item	7. Identification and Classification of the Subsidiary Which Acquired the    
        Security Being Reported on by theParent Holding Company or Control Person.

Not applicable.


Item	8. Identification and Classification of Members of the Group.

Not applicable.


Item	9. Notice of Dissolution of Group.

Not applicable.


Item	10. Certifications.

By signing below I certify that, to the best of my knowledge and belief, the 
securities referred to above were not acquired and are not heldfor the purpose 
of or with the effect of changing or influencing the control of the Issuer of 
the securities and were not acquired and are not held in connection with or as 
a participant in any transaction having that purpose or effect.

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CUSIP No: 30068X103    Page 12 of 12


                                   SIGNATURES                                   
After reasonable inquiry and to the best of its knowledge and belief, the 
undersigned certifies that the information set forth in thisstatement is true, 
complete, and correct.
Dated: February 13, 2024


                                                                 
TULLIS-DICKERSON CAPITAL FOCUS III, L.P.                         
                                                                 
By:  Tullis-Dickerson Partners III, L.L.C., its general partner  
                                                                 
By:  /s/ James L.L. Tullis                                       
     Name:                                James L.L. Tullis      
     Title:                               Manager                
                                                                 
TULLIS GROWTH FUND, L.P.                                         
                                                                 
By:  Tullis-Growth Partners, L.L.C., its general partner         
                                                                 
By:  /s/ James L.L. Tullis                                       
     Name:                                James L.L. Tullis      
     Title:                               Manager                
                                                                 
TULLIS GROWTH FUND II, L.P.                                      
                                                                 
By:  Tullis-Growth Partners II, L.L.C., its general partner      
                                                                 
By:  /s/ James L.L. Tullis                                       
     Name:                                James L.L. Tullis      
     Title:                               Manager                
                                                                 
TULLIS-DICKERSON PARTNERS III, L.L.C.                            
                                                                 
By:  /s/ James L.L. Tullis                                       
     Name:                                James L.L. Tullis      
     Title:                               Chief Executive Officer
                                                                 
TULLIS-GROWTH PARTNERS, L.L.C.                                   
                                                                 
By:  /s/ James L.L. Tullis                                       
     Name:                                James L.L. Tullis      
     Title:                               Manager                
                                                                 
TULLIS-GROWTH PARTNERS II, L.L.C.                                
                                                                 
By:  /s/ James L.L. Tullis                                       
     Name:                                James L.L. Tullis      
     Title:                               Chief Executive Officer
                                                                 
     /s/ James L.L. Tullis                                       
     JAMES L.L. TULLIS, Individually