Ownership Submission
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 OF SECURITIES

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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(Print or Type Responses)
1. Name and Address of Reporting Person *
Ciechanover Isaac E.
   2. Issuer Name and Ticker or Trading Symbol
Atara Biotherapeutics, Inc. [ATRA] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Executive Officer
(Last)
(First)
(Middle)
701 GATEWAY BOULEVARD, SUITE 200		 3. Date of Earliest Transaction (Month/Day/Year)
02/16/2016
(Street)

SOUTH SAN FRANCISCO, CA 94080		 4. If Amendment, Date 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
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 02/16/2016   M   5,908 A $ 0 (1) 217,321 D  
Common Stock               379,211 I See footnote (2)
Common Stock               450,824 I See footnote (3)
Common Stock               180,000 I See footnote (4)

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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 (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 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
(Month/Day/Year)		 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
Restricted Stock Units (5) 02/16/2016   M     5,908   (6)   (7) Common Stock 5,908 $ 0 45,292 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Ciechanover Isaac E.
701 GATEWAY BOULEVARD
SUITE 200
SOUTH SAN FRANCISCO, CA 94080		   X     Chief Executive Officer  

Signatures

 /s/ Tina Gullotta, Attorney-in-Fact for Isaac E. Ciechanover   02/18/2016
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) Shares issued upon settlement of vested restricted stock units ("RSUs").
(2) Shares are held by the Isaac E. Ciechanover and Allison M. Ciechanover Family Trust dated 8/8/08, of which the Reporting Person is a trustee.
(3) Sheld are held by the Ciechanover Family GRAT, of which the Reporting Person is a trustee.
(4) Sheld are held by the The Ciechanover 2015 GRAT, of which the Reporting Person is a trustee.
(5) Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock or a cash settlement.
(6) The RSUs were granted with both (a) a liquidity event-based vesting condition and (b) a service-based vesting condition, both of which conditions must be satisfied in order for the RSUs to vest. The liquidity event-based condition was satisfied upon the closing of the Issuer's initial public offering (the "IPO"). The shares that vested on the closing date of the IPO, and the shares that vested thereafter through May 15, 2015, were settled on May 15, 2015. The service-based vesting condition provides that 1/48th of the total number of shares shall vest monthly from January 10, 2014, subject to the holder's continuous service through each such date.
(7) The earlier of (i) January 10, 2021 or (ii) the recipient's termination date.

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