Ownership Submission

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

OMB APPROVAL

OMB Number:

3235-0104

Estimated average burden hours per response...

0.5

(Print or Type Responses)

1. Name and Address of Reporting Person ^*

MARCUS JOEL S

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)

C/O ALEXANDRIA REAL ESTATE EQUITIES, INC, 385 EAST COLORADO BOULEVARD, SUITE 299

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

__X__ Director	_____ 10% Owner
_____ Officer (give title below)	_____ Other (specify below)

5. If Amendment, Date Original Filed(Month/Day/Year)

(Street)

PASADENA, CA 91101

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)

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

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)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Series A Preferred Stock	⁽¹⁾	⁽¹⁾	Common Stock	256,410	$ ⁽¹⁾	I	See Footnote ⁽²⁾
Series B Preferred Stock	⁽³⁾	⁽³⁾	Common Stock	501,945	$ ⁽³⁾	I	See Footnote ⁽²⁾

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
MARCUS JOEL S C/O ALEXANDRIA REAL ESTATE EQUITIES, INC 385 EAST COLORADO BOULEVARD, SUITE 299 PASADENA, CA 91101	X

Signatures

/s/ Joel S. Marcus		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)	The Series A Preferred Stock has no expiration date and each share of Series A Preferred Stock will automatically convert into common stock on a 1-for-1 basis upon the consummation of the Issuer's initial public offering.
(2)	Consists of shares of common stock held by Alexandria Equities, LLC. Mr. Marcus is the Chairman, CEO and Founder of Alexandria Real Estate Equities, Inc., which is the managing member of Alexandria Equities, LLC, which has full voting and investment power with respect to the shares owned by Alexandria Equities, LLC. As an officer of Alexandria Real Estate Equities, Inc., Mr. Marcus may be deemed to have voting and investment power with respect to the shares owned by Alexandria Equities, LLC. Mr. Marcus disclaims beneficial ownership of the shares held by Alexandria Equities, LLC, except to the extent of his underlying pecuniary interest therein.
(3)	The Series B Preferred Stock has no expiration date and each share of Series B Preferred Stock will automatically convert into common stock on a 1-for-1 basis upon the consummation of the Issuer's initial public offering.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.