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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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Ciechanover Isaac E.
2. Date of Event Requiring Statement (Month/Day/Year)
10/15/2014
3. Issuer Name and Ticker or Trading Symbol
Atara Biotherapeutics, Inc. [ATRA]
(Last)
(First)
(Middle)
3260 BAYSHORE BOULEVARD
4. 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
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

BRISBANE, CA 94005
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 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 1,066,153
I
See Footnote (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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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 of Derivative Security: 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

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Ciechanover Isaac E.
3260 BAYSHORE BOULEVARD
BRISBANE, CA 94005
  X     Chief Executive Officer  

Signatures

/s/ Tina Gullotta, Attorney-in-Fact for Isaac C. Ciechanover 10/15/2014
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) Includes 577,500 shares held by the Isaac E. Ciechanover and Allison M. Ciechanover Family Trust dated 8/8/08, of which the Reporting Person is a trustee, and 488,653 shares held by the Ciechanover Family GRAT, of which the Reporting Person is a trustee.
 
Remarks:
As described in the issuer's registration statement on Form S-1 (File No. 333-196936) for the issuer's initial public offering (the "IPO"), the Reporting Person holds 94,523 restricted stock units (the "RSUs"), the vesting of which are subject to the satisfaction of both (a) a service-based condition and (b) a liquidity event-based condition. As a result, RSUs are not yet considered reportable for purposes of Section 16, and are not reflected on this Form 3. The liquidity event-based condition of the RSUs will be satisfied upon the closing of the IPO.

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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