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

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1. Name and Address of Reporting Person* ARCH Venture Fund XIII, L.P. (Last) (First) (Middle) 8755 W. HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 07/25/2025	3. Issuer Name and Ticker or Trading Symbol Lyell Immunopharma, Inc. [ LYEL ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X 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	938,438(1)	I	By: ARCH Venture Fund XIII, L.P.(2)

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)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* ARCH Venture Fund XIII, L.P. (Last) (First) (Middle) 8755 W. HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ARCH Venture Partners XIII, L.P. (Last) (First) (Middle) 8755 W. HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ARCH Venture Partners XIII, LLC (Last) (First) (Middle) 8755 W. HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* CRANDELL KEITH (Last) (First) (Middle) C/O ARCH VENTURE PARTNERS IX, LLC 8755 W. HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* NELSEN ROBERT (Last) (First) (Middle) 8755 W. HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Burow Kristina (Last) (First) (Middle) 8755 W. HIGGINS ROAD,SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* GILLIS STEVEN (Last) (First) (Middle) C/O ARCH VENTURE PARTNERS 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* BERNS PAUL L (Last) (First) (Middle) 8755 W. HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. These shares were purchased on July 25, 2025 pursuant to a securities purchase agreement dated July 24, 2025 at a price per share of $13.32.

2. These shares are directly held by ARCH Venture Fund XIII, L.P. ("ARCH XIII"). ARCH Venture Partners XIII, L.P. ("AVP XIII LP") is the general partner of ARCH XIII. ARCH Venture Partners XIII, LLC ("AVP XIII LLC") is the general partner of AVP XIII LP. Keith Crandell, Robert Nelsen, Kristina Burow, Paul Berns and Steven Gillis are members of the investment committee of AVP XIII LLC (the "AVP XIII LLC Committee Members"). Each of AVP XIII LP and AVP XIII LLC may be deemed to beneficially own the shares held by ARCH XIII, and each of the AVP XIII LLC Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XIII. Each of AVP XIII LP, AVP XIII LLC and the AVP XIII LLC Committee Members disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

	ARCH Venture Partners XIII, LLC, By: /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director	07/29/2025
	ARCH Venture Partners XIII, L.P., By: ARCH Venture Partners XIII, LLC, its General Partner, By: /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director	07/29/2025
	ARCH Venture Fund XIII, L.P., By: ARCH Venture Partners XIII, L.P., its General Partner, By: ARCH Venture Partners XIII, LLC, its General Partner, By: /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director	07/29/2025
	Keith Crandell, Managing Director, By: /s/ Mark McDonnell, as Attorney-in-Fact	07/29/2025
	Robert Nelsen, Managing Director, By: /s/ Mark McDonnell, as Attorney-in-Fact	07/29/2025
	Kristina Burow, Managing Director, By: /s/ Mark McDonnell, as Attorney-in-Fact	07/29/2025
	Steven Gillis, Managing Director, By: /s/ Mark McDonnell, as Attorney-in-Fact	07/29/2025
	Paul Berns, Managing Director, By: /s/ Mark McDonnell, as Attorney-in-Fact	07/29/2025
	** 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).
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