CNAT Conatus Pharmaceuticals Inc

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                                                                                   
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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 * Latterich Martin	2. Issuer Name and Ticker or Trading Symbol Histogen Inc. [ HSTO ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                    _____ 10% Owner __X__ Officer (give title below)    _____ Other (specify below) See Remarks
(Last)          (First)          (Middle) C/O HISTOGEN INC., 10655 SORRENTO VALLEY RD., STE 200	3. Date of Earliest Transaction (MM/DD/YYYY) 5/26/2020
(Street) SAN DIEGO, CA 92121 (City)        (State)        (Zip)	4. 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 Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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	5/26/2020		J	(1)	11951	A	$0.00	11951	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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
Stock Option (right to buy)	$3.70	10/7/2016		J		28684		(2)	10/7/2026	Common Stock	28684	$0.00	28684	D
Stock Option (right to buy)	$3.84	3/12/2018		J		14342		(3)	3/12/2028	Common Stock	14342	$0.00	14342	D

Explanation of Responses:
(1)	Shares of common stock of the corporation formerly known as Histogen Inc. ("Histogen") were converted into shares of common stock of the Issuer pursuant to that certain Agreement and Plan of Merger and Reorganization, dated as of January 28, 2020, by and among the Issuer, Chinook Merger Sub, Inc. and Histogen (the "Merger Agreement"). Pursuant to the terms of the Merger Agreement, each share of Histogen common stock was exchanged for 1.4342 shares of the Issuer's common stock (the "Conversion"). Immediately following the merger, the Issuer changed its name to Histogen Inc. All share numbers reflect the one-for-ten reverse stock split (the "Reverse Split") effected by the Issuer immediately prior to the completion of the merger.
(2)	Shares subject to the option vest in 48 equal monthly installments. Shares subject to the option and the exercise price have been adjusted based upon the Conversion and Reverse Split.
(3)	Shares subject to the option vest in 48 equal monthly installments. Shares subject to the option and the exercise price have been adjusted based upon the Conversion and Reverse Split.

Remarks: Vice President, Technical Operations

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Latterich Martin C/O HISTOGEN INC. 10655 SORRENTO VALLEY RD., STE 200 SAN DIEGO, CA 92121			See Remarks

Signatures
/s/ Richard W. Pascoe as attorney-in-fact for Martin Latterich		5/28/2020
**Signature of Reporting Person		Date