Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
Form 144

144: Issuer Information

Name of Issuer	Castle Biosciences, Inc.
SEC File Number	001-38984
Address of Issuer	820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546
Phone	1-602-535-1997
Name of Person for Whose Account the Securities are To Be Sold	Derek Maetzold
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Record	Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
#1	Common	Goldman Sachs & Co. LLC 200 West Street New York NEW YORK 10282	175,833	$3,870,084.33	26,575,616	05/04/2023	NASD

144: Securities To Be Sold

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

Record	Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
#1	Common	12/18/2020	Acquired as gift	Derek Maetzold	☒	10/29/2007	29,319	10/29/2007	N/A
#2	Common	12/18/2020	Acquired as gift	Derek Maetzold	☒	10/29/2007	29,318	10/29/2007	N/A
#3	Common	01/10/2022	Acquired as gift	Derek Maetzold	☒	10/29/2007	14,641	10/29/2007	N/A
#4	Common	01/10/2022	Acquired as gift	Derek Maetzold	☒	10/29/2007	14,639	10/29/2007	N/A
#5	Common	01/10/2022	Acquired as gift	Derek Maetzold	☒	10/29/2007	14,639	10/29/2007	N/A
#6	Common	01/10/2022	Acquired as gift	Derek Maetzold	☒	10/29/2007	14,639	10/29/2007	N/A
#7	Common	10/29/2007	Acquired from issuer in private transaction	Issuer	☐	—	44,338	10/29/2007	N/A
#8	Common	12/09/2022	Acquired as compensation -- RSUs	Issuer	☐	—	14,300	12/09/2022	Compensation

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

144: Securities Sold During The Past 3 Months

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

Record	Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
#1	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/03/2023	1,196	$26,486.26
#2	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/03/2023	597	$13,220.98
#3	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/03/2023	597	$13,220.98
#4	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/03/2023	2,391	$52,950.37
#5	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/03/2023	1,196	$26,486.26
#6	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/03/2023	597	$13,220.98
#7	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/03/2023	596	$13,198.84
#8	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/13/2023	912	$20,681.15
#9	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/13/2023	455	$10,317.90
#10	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/13/2023	455	$10,317.90
#11	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/13/2023	1,823	$41,339.62
#12	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/13/2023	912	$20,681.15
#13	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/13/2023	455	$10,317.90
#14	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/13/2023	455	$10,317.90
#15	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/12/2023	484	$10,944.21
#16	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/12/2023	242	$5,472.10
#17	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/12/2023	242	$5,472.10
#18	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/12/2023	969	$21,911.03
#19	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/12/2023	484	$10,944.21
#20	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/12/2023	242	$5,472.10
#21	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/12/2023	242	$5,472.10
#22	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/13/2023	152	$3,992.17
#23	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/13/2023	76	$1,996.09
#24	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/13/2023	76	$1,996.09
#25	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/13/2023	303	$7,958.08
#26	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/13/2023	152	$3,992.17
#27	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/13/2023	76	$1,996.09
#28	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/13/2023	75	$1,969.82
#29	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/14/2023	1,396	$29,251.92
#30	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/14/2023	697	$14,605.01
#31	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/14/2023	697	$14,605.01
#32	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/14/2023	2,792	$58,503.85
#33	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/14/2023	1,396	$29,251.92
#34	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/14/2023	697	$14,605.01
#35	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/14/2023	697	$14,605.01
#36	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/04/2023	200	$4,420.20
#37	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/04/2023	100	$2,210.10
#38	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/04/2023	100	$2,210.10
#39	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/04/2023	401	$8,862.50
#40	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/04/2023	200	$4,420.20
#41	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/04/2023	100	$2,210.10
#42	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	04/04/2023	101	$2,232.20
#43	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/10/2023	1,244	$32,556.23
#44	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/10/2023	621	$16,251.94
#45	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/10/2023	621	$16,251.94
#46	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/10/2023	2,489	$65,138.62
#47	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/10/2023	1,244	$32,556.23
#48	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/10/2023	621	$16,251.94
#49	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	02/10/2023	622	$16,278.11
#50	The Maetzold Descendants 2020 Trust dtd 12/4/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/06/2023	1,396	$34,492.65
#51	The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/06/2023	697	$17,221.62
#52	The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/06/2023	697	$17,221.62
#53	Derek Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/06/2023	2,792	$68,985.29
#54	Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/06/2023	1,396	$34,492.65
#55	The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/06/2023	697	$17,221.62
#56	The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 820 S FRIENDSWOOD DR SUITE 201 FRIENDSWOOD TEXAS 77546	Common	03/06/2023	697	$17,221.62

144: Remarks and Signature

Remarks	Total number of shares to be sold includes: 58,638 shares by Derek Maetzold, 29,318 shares by DM 2020 Irrev Tr, 29,319 shares by Maetzold Descendants 2020 Tr, 14,639 shares by Hannah Maetzold Irrev. Trust, 14,639 shares by Peter Maetzold Irrev. Trust, 14,641 shares by Emily Maetzold Irrev. Trust, 14,639 shares by John Maetzold Irrev. Trust. The sales of shares set forth herein are made in connection with a selling plan dated 12/12/2022 that is intended to comply with Rule 10b5-1(c).
Date of Notice	05/04/2023
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	12/12/2022
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	Goldman Sachs & Co. LLC on behalf of Derek Maetzold
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)