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 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 *
Kleiner Perkins Caufield & Byers XV, LLC
   2. Issuer Name and Ticker or Trading Symbol
Atara Biotherapeutics, Inc. [ATRA] 		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)
2750 SAND HILL ROAD		 3. Date of Earliest Transaction (Month/Day/Year)
10/21/2014
(Street)

MENLO PARK, CA 94025		 4. If Amendment, Date Original Filed(Month/Day/Year)
 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 (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 10/21/2014   C   1,852,106 A (1) 2,599,029 I See Footnote (2)
Common Stock 10/21/2014   C   55,314 A (1) 77,621 I See Footnote (3)

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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
Series A Preferred Stock (1) 10/21/2014   C     1,244,871   (1)   (1) Common Stock 1,244,871 $ 0 0 I See Footnote (2)
Series B Preferred Stock (1) 10/21/2014   C     607,234   (1)   (1) Common Stock 607,235 $ 0 0 I See Footnote (2)
Series A Preferred Stock (1) 10/21/2014   C     37,179   (1)   (1) Common Stock 37,179 $ 0 0 I See Footnote (3)
Series B Preferred Stock (1) 10/21/2014   C     18,136   (1)   (1) Common Stock 18,135 $ 0 0 I See Footnote (3)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Kleiner Perkins Caufield & Byers XV, LLC
2750 SAND HILL ROAD
MENLO PARK, CA 94025		     X    
KPCB XV Associates, LLC
2750 SAND HILL ROAD
MENLO PARK, CA 94025		     X    
KPCB XV Founders Fund, LLC
2750 SAND HILL ROAD
MENLO PARK, CA 94025		     X    

Signatures

 /s/ Paul Vronsky, General Counsel   10/23/2014
**Signature of Reporting Person Date
 /s/ Paul Vronsky, General Counsel   10/23/2014
**Signature of Reporting Person Date
 /s/ Paul Vronsky, General Counsel   10/23/2014
**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) Each share of preferred stock converted into one share of the Issuer's Common Stock upon the closing of the Issuer's initial public offering. The shares had no expiration date.
(2) The shares are directly held by Kleiner Perkins Caufield & Byers XV, LLC ("KPCB XV"). All shares are held for convenience in the name of "KPCB Holdings, Inc., as nominee". The managing member of KPCB XV is KPCB XV Associates, LLC ("XV Associates"). The voting and dispositive control over the shares is shared by individual managing members of XV Associates, none of whom has veto power.
(3) The shares are directly held by KPCB XV Founders Fund, LLC ("KPCB XV FF"). All shares are held for convenience in the name of "KPCB Holdings, Inc., as nominee". The managing member of KPCB XV FF is XV Associates. The voting and dispositive control over the shares is shared by individual managing members of XV Associates, none of whom has veto power.
 
Remarks:
KPCB XV Associates and its respective managing members disclaim beneficial ownership of these shares except to the extent of any pecuniary interest therein, and the filing of this report is not an admission that any of them is the beneficial owner of these shares for purposes of Section 16 or for any other purpose.

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