SEC FORM 3

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

Yamada Tadataka

(Last)

(First)

(Middle)

C/O PROMETHEUS BIOSCIENCES, INC.

9410 CARROLL PARK DRIVE

(Street)

SAN DIEGO

92121

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
03/11/2021

3. Issuer Name and Ticker or Trading Symbol
Prometheus Biosciences, Inc. [ RXDX ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
and Chairman of the Board

5. If Amendment, Date of 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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Series B Preferred Stock	⁽¹⁾	⁽¹⁾	Common Stock	13,333	⁽¹⁾	D
Stock Option (Right to Buy)	⁽²⁾	09/11/2027	Common Stock	25,000	0.5	D
Stock Option (Right to Buy)	⁽³⁾	11/29/2027	Common Stock	15,000	0.5	D
Stock Option (Right to Buy)	⁽⁴⁾	05/22/2028	Common Stock	100,000	0.5	D
Stock Option (Right to Buy)	⁽⁵⁾	12/17/2030	Common Stock	114,040	3.7	D
Stock Option (Right to Buy)	⁽⁶⁾	02/03/2031	Common Stock	135,913	6.7	D

Explanation of Responses:

1. Shares of Series B Preferred Stock are convertible at any time, at the holder's election, at a ratio of ten-for-one share of the Issuer's common stock. In addition, effective immediately prior to the closing of the Issuer's initial public offering of its common stock, each share of Series B Preferred Stock will automatically convert at the ratio of ten-for-one share of the Issuer's common stock. The Series B Preferred Stock has no expiration date.

2. 25% of the shares subject to the option will vest on September 12, 2018, and 1/48th of the shares subject to the option will vest monthly thereafter, subject to the Report Person's continued service with the Issuer through each vest date.

3. 25% of the shares subject to the option will vest on November 30, 2018, and 1/48th of the shares subject to the option will vest monthly thereafter, subject to the Report Person's continued service with the Issuer through each vest date.

4. 25% of the shares subject to the option will vest on May 23, 2019, and 1/48th of the shares subject to the option will vest monthly thereafter, subject to the Report Person's continued service with the Issuer through each vest date.

5. 25% of the shares subject to the option will vest on November 5, 2021, and 1/48th of the shares subject to the option will vest monthly thereafter, subject to the Report Person's continued service with the Issuer through each vest date.

6. 25% of the shares subject to the option will vest on February 4, 2022, and 1/48th of the shares subject to the option will vest monthly thereafter, subject to the Report Person's continued service with the Issuer through each vest date.

Remarks:

	/s/Timothy K. Andrews, attorney-in-fact for Tadataka Yamada	03/11/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.