Sec Form 4 Filing - Third Rock Ventures III, L.P. @ Revolution Medicines, Inc. - 2020-02-18

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 Third Rock Ventures III, L.P. 2. Issuer Name and Ticker or Trading Symbol Revolution Medicines, Inc. [ RVMD] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O THIRD ROCK VENTURES, LLC,, 29 NEWBURY STREET, 3RD FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 02/18/2020 (Street) BOSTON, MA02116 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 Common Stock 02/18/2020 C 8,613,025 ( 1 ) A 9,024,031 D ( 3 ) Common Stock 02/18/2020 C 1,909,317 ( 4 ) A 1,909,317 D ( 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 Series A Preferred Stock ( 2 ) 02/18/2020 C 8,220,641 ( 2 ) ( 2 ) Common Stock 8,220,641 $ 0 0 D ( 3 ) Series B Preferred Stock ( 2 ) 02/18/2020 C 342,505 ( 2 ) ( 2 ) Common Stock 342,505 $ 0 0 D ( 3 ) Series C Preferred Stock ( 2 ) 02/18/2020 C 49,879 ( 2 ) ( 2 ) Common Stock 49,879 $ 0 0 D ( 3 ) Series B Preferred Stock ( 2 ) 02/18/2020 C 1,909,317 ( 2 ) ( 2 ) Common Stock 1,909,317 $ 0 0 D ( 5 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Third Rock Ventures III, L.P. C/O THIRD ROCK VENTURES, LLC, 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X Third Rock Ventures GP III, L.P. 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X TRV GP III, LLC 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X Third Rock Ventures II, L.P. 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X Third Rock Ventures GP II, L.P. 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X TRV GP II, LLC 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X LEVIN MARK J C/O THIRD ROCK VENTURES, LLC 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X STARR KEVIN P C/O THIRD ROCK VENTURES, LLC 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X TEPPER ROBERT I C/O THIRD ROCK VENTURES, LLC 29 NEWBURY STREET, 3RD FLOOR BOSTON, MA02116 X Signatures /s/ Kevin Gillis, Chief Operating Officer of TRV GP III, LLC, general partner of Third Rock Ventures GP III, L.P., general partner of Third Rock Ventures III, L.P. 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis, Chief Operating Officer of TRV GP III, LLC, general partner of Third Rock Ventures GP III, L.P. 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis, Chief Operating Officer of TRV GP III, LLC 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis, Chief Operating Officer of TRV GP II, LLC, general partner of Third Rock Ventures GP II, L.P., general partner of Third Rock Ventures II, L.P. 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis, Chief Operating Officer of TRV GP II, LLC, general partner of Third Rock Ventures GP II, L.P. 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis, Chief Operating Officer of TRV GP II, LLC 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis by power of attorney for Mark Levin 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis by power of attorney for Kevin Starr 02/18/2020 Signature of Reporting Person Date /s/ Kevin Gillis by power of attorney for Robert Tepper 02/18/2020 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents the total number of shares of Common Stock received by Third Rock Ventures III, L.P. ("TRV III") upon conversion of the Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock of the Issuer in connection with the closing of the Issuer's initial public offering. ( 2 )The Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock were convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Preferred Stock had no expiration date. ( 3 )These shares are directly held by TRV III. The general partner of TRV III is Third Rock Ventures GP III, L.P. ("TRV GP III"). The general partner of TRV GP III is TRV GP III, LLC ("TRV GP III LLC"). The individual managers of TRV GP III LLC are Mark Levin ("Levin"), Kevin Starr ("Starr") and Dr. Robert Tepper ("Tepper"). Each of TRV GP III, TRV GP III LLC, Levin, Starr and Tepper disclaims beneficial ownership of these shares except to the extent of its or his pecuniary interest therein, if any, and this report shall not be deemed an admission that it or he is the beneficial owner of such shares. ( 4 )Represents the total number of shares of Common Stock received by Third Rock Ventures II, L.P. ("TRV II") upon conversion of the Series B Preferred Stock of the Issuer in connection with the closing of the Issuer's initial public offering. ( 5 )These shares are directly held by TRV II. The general partner of TRV II is Third Rock Ventures GP II, L.P. ("TRV GP II"). The general partner of TRV GP II is TRV GP II, LLC ("TRV GP II LLC"). The individual managers of TRV GP II LLC are Levin, Starr and Tepper. Each of TRV GP II, TRV GP II LLC, Levin, Starr and Tepper disclaims beneficial ownership of these shares except to the extent of its or his pecuniary interest therein, if any, and this report shall not be deemed an admission that it or he is the beneficial owner of such shares.

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).

** 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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