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, 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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(Print or Type Responses)
1. Name and Address of Reporting Person *
MARCUS JOEL S
  2. Issuer Name and Ticker or Trading Symbol
Atara Biotherapeutics, Inc. [ATRA]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O ALEXANDRIA REAL ESTATE EQUITIES, INC, 385 EAST COLORADO BOULEVARD, SUITE 299
3. Date of Earliest Transaction (Month/Day/Year)
02/27/2019
(Street)

PASADENA, CA 91101
4. If Amendment, Date Original Filed(Month/Day/Year)
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 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 02/27/2019   M   25,000 A $ 25.15 32,590 D  
Common Stock 02/27/2019   M   10,500 A $ 24.05 43,090 D  
Common Stock 02/27/2019   M   5,500 A $ 15.08 48,590 D  
Common Stock 02/27/2019   M   21,500 A $ 13.2 70,090 D  
Common Stock 02/28/2019   S   62,590 D $ 36.07 (1) 7,500 D  
Common Stock               4,000 I Held by the Joel S. Marcus and Barbara A. Marcus Family Trust
Common Stock               908,355 I See footnote (2)

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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
Non-Qualified Stock Option (Right to Buy) $ 25.15 02/27/2019   M     25,000   (3) 01/16/2022 Common Stock 25,000 $ 0 0 D  
Non-Qualified Stock Option (Right to Buy) $ 24.05 02/27/2019   M     10,500   (3) 01/04/2023 Common Stock 10,500 $ 0 0 D  
Non-Qualified Stock Option (Right to Buy) $ 15.08 02/27/2019   M     5,500   (3) 01/03/2024 Common Stock 5,500 $ 0 0 D  
Non-Qualified Stock Option (Right to Buy) $ 13.2 02/27/2019   M     21,500   (3) 06/08/2024 Common Stock 21,500 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 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/ David Tucker, Attorney-in-Fact   03/01/2019
**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) The price in Column 4 is a weighted average sale price. The prices actually received ranged from $35.75 to $36.72. The reporting person will provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.
(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) Fully vested.

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