X0206 3 2019-07-24 0 0001447362 CASTLE BIOSCIENCES INC CSTL 0001024008 KABAKOFF DAVID S C/O CASTLE BIOSCIENCES, INC. 820 S. FRIENDSWOOD DRIVE, SUITE 201 FRIENDSWOOD TX 77546 1 0 1 0 Stock Option (right to buy) 16.00 2029-07-23 Common Stock 30895 D Series A Preferred Stock Common Stock 16015 I By L.P. Series E-2 Preferred Stock Common Stock 358416 I By L.P. Series E-3 Preferred Stock Common Stock 318842 I By L.P. Series F Preferred Stock Common Stock 982785 I By L.P. Convertible Promissory Note Common Stock 1027882.00 I By L.P. Warrant to purchase Series F Preferred Stock 0.01 2023-01-12 Series F Preferred Stock 14107 I By L.P. 25% of the shares shall vest on August 1, 2020, and the remaining shares shall vest in 36 equal monthly installments thereafter. All outstanding shares of Preferred Stock will automatically convert into shares of Common Stock immediately upon the closing of the Issuer's initial public offering (the "IPO"), for no additional consideration at a rate of 1 share of Common Stock for each 1.219 shares of Preferred Stock, based on the conversion price currently in effect. The Preferred Stock has no expiration date. Held by Sofinnova HealthQuest Partners, L.P., or HealthQuest Partners. HealthQuest Venture Management, L.L.C., or HealthQuest Management, is the managing member of HealthQuest Partners. David Kabakoff, Ph.D., the Reporting Person, is a partner of HealthQuest Management. Garheng Kong is the managing member of HealthQuest Partners 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. The principal amount of the Convertible Promissory Note held by the designated Reporting Person is $1,027,882.00. Upon closing of the IPO, all unpaid principal and accrued interest outstanding on the Convertible Promissory Note (the "Conversion Amount") will automatically convert into the number of shares of Common Stock that is equal to the Conversion Amount as of the closing date divided by 80% of the IPO price per share. Immediately exercisable. In the event of the IPO, the warrant will expire at the closing of the IPO if not exercised. Immediately prior to the closing of the IPO, the warrant will become exercisable for 11,572 shares of Common Stock. /s/ Greg Acosta, Attorney-in-fact 2019-07-24