FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
MCGUIRE TERRANCE
  2. Issuer Name and Ticker or Trading Symbol
Cyclerion Therapeutics, Inc. [CYCN] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O CYCLERION THERAPEUTICS, INC., 245 FIRST STREET, 18TH FLOOR		 3. Date of Earliest Transaction (Month/Day/Year)
11/30/2023
(Street)

CAMBRIDGE, MA 02142		 4. If Amendment, Date Original Filed (Month/Day/Year)
 6. Individual or Joint/Group Filing (Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3) 		2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8) 		4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5) 		5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4) 		6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4) 		7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 11/30/2023   A   5,000 (1) A $ 0 5,552 D  
Common Stock               34,866 I By Polaris Partners VIII, L.P (2)
Common Stock               1,247 I By Polaris Entrepreneurs 'Fund VIII, L.P. (3)
Common Stock               345 I By Bartlett Partners, LLC (4)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3) 		2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8) 		5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5) 		6. Date Exercisable and Expiration Date
(Month/Day/Year) 		7. Title and Amount of Underlying Securities
(Instr. 3 and 4) 		8. Price of Derivative Security
(Instr. 5) 		9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4) 		10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4) 		11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MCGUIRE TERRANCE
C/O CYCLERION THERAPEUTICS, INC.
245 FIRST STREET, 18TH FLOOR
CAMBRIDGE, MA 02142		   X      

Signatures

 /s/ Lauren Crockett, Attorney-in-Fact   12/04/2023
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The Reporting Person was granted 5,000 shares of restricted stock pursuant to the Cyclerion Therapeutics, Inc. 2019 Equity Incentive Plan. 2,500 of these shares vest immediately and the remaining 2,500 of these shares vest over the next 6 months, provided that the Reporting Person remains as a director of Cylerion Therapeutics, Inc. on such applicable vesting date, subject to certain exemptions.
(2) The reportable securities are owned directly by Polaris Partners VIII, L.P. ("PP VIII"). Polaris Partners GP VIII, L.L.C. ("PPGP VIII") is the general partner of PP VIII. The Reporting Person, a member of the Issuer's Board of Directors, is an interest holder of PPGP VIII. Each of David Barrett, Brian Chee, Amir Nashat and Bryce Youngren are the managing members of PPGP VIII (collectively, the "Managing Members"). Each of the Reporting Person and the Managing Members, in their respective capacities with respect to PPGP VIII, may be deemed to have shared voting and dispositive power over the shares held by PP VIII. Each of PPGP VIII, the Reporting Person and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.
(3) The reportable securities are owned directly by PEF VIII. PPGP VIII is the general partner of PEF VIII. The Reporting Person, a member of the Issuer's Board of Directors, is an interest holder of PPGPVIII. Each of the Reporting Person and the Managing Members, in their respective capacities with respect to PPGP VIII, may be deemed to have shared voting and dispositive power over the shares held by PEF VIII. Each of PPGP VIII, the Reporting Person and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.
(4) The Reporting Person is a managing member of Bartlett Partners, LLC, the beneficial owner of the securities. The Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that he is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of his pecuniary interest therein.

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