Statement of Changes in Beneficial Ownership (4)

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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3235-0287

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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 * KABAKOFF DAVID S	2. Issuer Name and Ticker or Trading Symbol CASTLE BIOSCIENCES INC [ CSTL ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director                    __X__ 10% Owner _____ Officer (give title below)    _____ Other (specify below)
(Last)          (First)          (Middle) C/O CASTLE BIOSCIENCES, INC., 820 S. FRIENDSWOOD DRIVE, SUITE 201	3. Date of Earliest Transaction (MM/DD/YYYY) 2/19/2020
(Street) FRIENDSWOOD, TX 77546 (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	2/19/2020		S(1)		25000	D	$32.03	1683577	I	By L.P. (2)

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

Explanation of Responses:
(1)	The transaction on this Form 4 was made pursuant to a Rule 10b5-1 plan adopted by Sofinnova HealthQuest Partners, L.P. on December 17, 2019.
(2)	Held by Sofinnova HealthQuest Partners, L.P., or HealthQuest Partners. HealthQuest Venture Management, L.L.C., or HealthQuest Management, is the general partner of HealthQuest Partners. David Kabakoff, Ph.D., the Reporting Person, is a partner of HealthQuest Management. Garheng Kong is the managing member of HealthQuest Management and has sole voting and investment power over the shares held by HealthQuest Partners. Each of HealthQuest Management, Mr. Kong and Dr. Kabakoff disclaims beneficial ownership over all shares held by HealthQuest Partners except to the extent of any pecuniary interest therein.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
KABAKOFF DAVID S C/O CASTLE BIOSCIENCES, INC. 820 S. FRIENDSWOOD DRIVE, SUITE 201 FRIENDSWOOD, TX 77546	X	X

Signatures
/s/ Greg Acosta, Attorney-in-fact		2/21/2020
**Signature of Reporting Person		Date