Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^*

Hyllengren Eric J

2. Date of Event Requiring Statement (MM/DD/YYYY) 4/1/2023

3. Issuer Name and Ticker or Trading Symbol

Atara Biotherapeutics, Inc. [ATRA]

(Last) (First) (Middle)

C/O ATARA BIOTHERAPEUTICS, INC., 2380 CONEJO SPECTRUM STREET, SUITE 200

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

_____ Director _____ 10% Owner
___X___ Officer (give title below) _____ Other (specify below)
SVP, CFO /

(Street)

THOUSAND OAKS, CA 91320

(City) (State) (Zip)

5. If Amendment, Date Original Filed(MM/DD/YYYY)

6. Individual or Joint/Group Filing(Check Applicable Line)

_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

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)
Common Stock	234060 ⁽¹⁾⁽²⁾	D

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		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 Derivate 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)
Employee Stock Option (Right to Buy)	8/20/2022	9/3/2025	Common Stock	47500	$39.85	D
Employee Stock Option (Right to Buy)	2/6/2023	2/5/2029	Common Stock	11500	$38.47	D
Employee Stock Option (Right to Buy)	4/1/2023	2/28/2030	Common Stock	12526	$12.15	D
Employee Stock Option (Right to Buy)	⁽³⁾	2/28/2030	Common Stock	3724	$12.15	D
Employee Stock Option (Right to Buy)	4/1/2023	2/28/2031	Common Stock	9530	$17.105	D
Employee Stock Option (Right to Buy)	⁽⁴⁾	2/28/2031	Common Stock	8768	$17.105	D
Employee Stock Option (Right to Buy)	4/1/2023	2/29/2032	Common Stock	6540	$10.21	D
Employee Stock Option (Right to Buy)	⁽⁵⁾	2/29/2032	Common Stock	17608	$10.21	D
Employee Stock Option (Right to Buy)	4/1/2023	2/28/2033	Common Stock	8298	$3.91	D
Employee Stock Option (Right to Buy)	⁽⁵⁾	2/28/2033	Common Stock	290417	$3.91	D

Explanation of Responses:
(1)	Includes an aggregate 194,599 restricted stock units ("RSUs"), which are comprised of: (i) 5,297 RSUs that vest as to 1/4th of the shares on May 15, 2023 and each of the next three (3) "Quarterly Vesting Dates" (as defined herein); (ii) 6,066 RSUs that vest as to 1/8th of shares on May 15, 2023 and each of the next seven (7) Quarterly Vesting Dates; (iii) 18,697 RSUs that vest as to 1/3rd of shares on November 15, 2023, November 15, 2024 and November 15, 2025; (iv) 11,777 RSUs that vest as to 1/12th of shares on May 15, 2023 and each of the next eleven (11) Quarterly Vesting Dates; (v) 20,000 RSUs that vest as to 1/2nd of shares on November 15, 2023 and 1/2nd on November 15, 2024; and (vi) 132,762 RSUs that vest as to 1/12th of shares on May 15, 2023 and each of the next eleven (11) Quarterly Vesting Dates, each of which is subject to the reporting person's continuous service.
(2)	"Quarterly Vesting Date" means March 1, May 15, August 15, and November 15 of each year, provided that if such date falls on a weekend or holiday, the "Quarterly Vesting Date" shall be the first (1st) business day after such date.
(3)	1/11th of shares subject to the stock option vest and become exercisable on May 1, 2023, and the remaining shares vest in equal monthly installments over the following ten (10) months, subject to the reporting person's continuous service.
(4)	1/23rd of shares subject to the stock option vest and become exercisable on May 1, 2023, and the remaining shares vest in equal monthly installments over the following twenty-two (22) months, subject to the reporting person's continuous service.
(5)	1/35th of shares subject to the stock option vest and become exercisable on May 1, 2023, and the remaining shares vest in equal monthly installments over the following thirty-four (34) months, subject to the reporting person's continuous service.

Remarks:
Exhibit 24 - Power of Attorney

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Hyllengren Eric J C/O ATARA BIOTHERAPEUTICS, INC. 2380 CONEJO SPECTRUM STREET, SUITE 200 THOUSAND OAKS, CA 91320			SVP, CFO

Signatures
/s/ Jeff Kiekhofer, Attorney-in-Fact for Eric J. Hyllengren		4/7/2023
^**Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	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).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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