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 or Section 30(h) of the Investment Company Act of 1940

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3235-0287

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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)
05/14/2015

(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)
1.Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/14/2015		J		194,200	D	$ 0 ⁽¹⁾	2,404,828 ⁽²⁾	I	See Footnote ⁽³⁾
Common Stock	05/14/2015		J		5,800	D	$ 0 ⁽⁴⁾	71,822 ⁽²⁾	I	See Footnote ⁽⁵⁾

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

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

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	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		05/18/2015
^**Signature of Reporting Person		Date
/s/Paul Vronsky, Attorney-in-Fact		05/18/2015
^**Signature of Reporting Person		Date
/s/Paul Vronsky, Attorney-in-Fact		05/18/2015
^**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)	Pro rata distribution to the members of Kleiner Perkins Caufield & Byers XV, LLC ("KPCB XV") pursuant to the terms of its operating agreement.
(2)	Ending balance reflects correction of 1 share reallocation from KPCB XV to KPCB XV Founders Fund, LLC ("KPCB XV FF"). Allocations in the original Form 3 reflected 2,599,029 shares held by KPCB XV and 77,621 shares held by KPCB XV FF.
(3)	The shares are directly held by 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.
(4)	Pro rata distribution to the members of KPCB XV FF pursuant to the terms of its operating agreement.
(5)	The shares are directly held by 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.

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