Sec Form 4 Filing - Meister Keith A. @ Sema4 Holdings Corp. - 2022-04-29

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 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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1. Name and Address of Reporting Person Meister Keith A. 2. Issuer Name and Ticker or Trading Symbol Sema4 Holdings Corp. [ SMFR] 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 CORVEX MANAGEMENT LP, 667 MADISON AVENUE 3. Date of Earliest Transaction (MM/DD/YY) 04/29/2022 (Street) NEW YORK, NY10065 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 Class A Common Stock 04/29/2022 P 11,437,500 A $ 4 26,931,250 I See footnotes( 1 )( 2 )( 3 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Meister Keith A. C/O CORVEX MANAGEMENT LP 667 MADISON AVENUE NEW YORK, NY10065 X Signatures /s/ Keith A. Meister 05/03/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Investment funds advised by Corvex Management LP are the record holders of 15,937,500 shares of the Class A common stock, par value $0.0001 per share ("Class A Common Stock") reported herein. Mr. Meister may be deemed to be indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex Management LP. ( 2 )CMLS Holdings LLC ("CMLS Holdings") is the record holder of 10,993,750 shares of the Class A common stock, par value $0.0001 per share ("Class A Common Stock") reported herein. Mr. Meister is one of two members of the Board of Managers of CMLS Holdings, and Mr. Meister shares voting and investment discretion with respect to the securities held of record by CMLS Holdings.Stock") reported herein. Mr. Meister is one of two members of the Board of Managers of CMLS Holdings, and Mr. Meister shares voting and investment discretion with respect to the securities held of record by CMLS Holdings. ( 3 )For the purposes of this filing, Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein. This filing shall not be deemed an admission that Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.This filing shall not be deemed an admission that Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

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 4(b)(v).

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