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* Dier Mardi (Last) (First) (Middle) C/O ACELYRIN, INC. 4149 LIBERTY CANYON RD. (Street) AGOURA HILLS CA 91301 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 05/04/2023	3. Issuer Name and Ticker or Trading Symbol ACELYRIN, Inc. [ SLRN ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) CFO and CBO	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)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (right to buy)	(1)	11/20/2032	Class A Common Stock(2)	673,621	5.8766	D

Explanation of Responses:

1. 1/4 of the shares subject to the option vest on November 15, 2023, and 1/48 of the shares subject to the option vests in equal monthly installments thereafter, subject to the Reporting Person's continued service.

2. Each share of Class A Common Stock shall be reclassified into one share of Common Stock immediately prior to the completion of the Issuer's initial public offering of Common Stock.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Mina Kim, Attorney-in-fact	05/04/2023
	** 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.
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POWER OF ATTORNEY
Know all by these presents, that the undersigned hereby constitutes and appoints
each of Mina Kim, Sanampreet Pangali, Eddie Kim, Charles Kim, Chadwick Mills,
Anitha Anne, and Brian Youn, signing individually, the undersigned's true and
lawful attorneys-in fact and agents to:

(1) execute for and on behalf of the undersigned, in the undersigned's capacity
as an officer, director and/or greater than 10% stockholder of ACELYRIN, Inc.
(the "Company"), Forms 3, 4 and 5 (including any amendments thereto) in
accordance with Section 16(a) of the Securities Exchange Act of 1934, as amended
(the "Exchange Act"), and the rules thereunder;

(2) do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Forms 3, 4 or 5
(including any amendments thereto) and timely file such forms with the
Securities and Exchange Commission and any stock exchange or similar authority;
and

(3) take any other action of any nature whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be
done by virtue of this power of attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Exchange Act.

This Power of Attorney shall remain in full force and effect until the earliest
to occur of (a) the undersigned is no longer required to file Forms 3, 4 and 5
with respect to the undersigned's holdings of and transactions in securities
issued by the Company, (b) revocation by the undersigned in a signed writing
delivered to the foregoing attorneys-in-fact or (c) as to any attorney-in-fact
individually, until such attorney-in-fact is no longer employed by the Company
or employed by or a partner at Cooley LLP, as applicable.

The undersigned has caused this Power of Attorney to be executed as of April 3,
2023.

/s/ Mardi C. Dier