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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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)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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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