Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^*

Peterson Caryn

2. Date of Event Requiring Statement (MM/DD/YYYY) 4/16/2021

3. Issuer Name and Ticker or Trading Symbol

Gossamer Bio, Inc. [GOSS]

(Last) (First) (Middle)

3013 SCIENCE PARK ROAD

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

_____ Director _____ 10% Owner
___X___ Officer (give title below) _____ Other (specify below)
EVP, Regulatory Affairs /

(Street)

SAN DIEGO, CA 92121

(City) (State) (Zip)

5. If Amendment, Date Original Filed(MM/DD/YYYY)

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)
Common Stock	64008 ⁽¹⁾	D

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivate Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option (Right to Buy)	⁽²⁾	5/21/2028	Common Stock	86444.0	$2.61	D
Stock Option (Right to Buy)	⁽³⁾	12/10/2028	Common Stock	48888.0	$10.71	D
Stock Option (Right to Buy)	⁽⁴⁾	3/25/2029	Common Stock	48500.0	$22.1	D
Stock Option (Right to Buy)	⁽⁵⁾	12/23/2029	Common Stock	13750.0	$16.4	D
Stock Option (Right to Buy)	⁽⁶⁾	2/14/2030	Common Stock	34175.0	$14.55	D
Stock Option (Right to Buy)	⁽⁷⁾	2/25/2031	Common Stock	28250.0	$9.79	D

Explanation of Responses:
(1)	Includes 54,427 restricted stock unit awards, which will vest in accordance with the terms of each award and subject to the Reporting Person's continuous service to the Issuer on each vesting date.
(2)	64,840 shares subject to the option have vested and are fully exerciseable and 1/48th of the total number of shares subject to the option vest on April 21, 2021 and the last day of each one-month period thereafter through May 21, 2022, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.
(3)	28,540 shares subject to the option have vested and are fully exerciseable and 1/48th of the total number of shares subject to the option vest on May 10, 2021 and the last day of each one-month period thereafter through December 10, 2022, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.
(4)	24,250 shares subject to the option have vested and are fully exerciseable and 1/48th of the total number of shares subject to the option vest on April 25, 2021 and the last day of each one-month period thereafter through March 25, 2023, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.
(5)	4,296 shares subject to the option have vested and are fully exerciseable and 1/48th of the total number of shares subject to the option vest on April 23, 2021 and the last day of each one-month period thereafter through December 23, 2023, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.
(6)	9,967 shares subject to the option have vested and are fully exerciseable and 1/48th of the total number of shares subject to the option vest on May 14, 2021 and the last day of each one-month period thereafter through February 14, 2024, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.
(7)	25% of the total number of shares subject to the option will vest on February 25, 2022 and 1/48th of the total number of shares subject to the option vest on the last day of each one-month period thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Remarks:
Exhibit 24 - Power of Attorney

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Peterson Caryn 3013 SCIENCE PARK ROAD SAN DIEGO, CA 92121			EVP, Regulatory Affairs