X0206 3 2019-07-24 0 0001447362 CASTLE BIOSCIENCES INC CSTL 0001236397 BRADBURY DANIEL C/O CASTLE BIOSCIENCES, INC. 820 S. FRIENDSWOOD DRIVE, SUITE 201 FRIENDSWOOD TX 77546 1 0 0 0 Stock option (right to buy) 16.00 2019-07-23 Common Stock 30895 D Series A Preferred Stock Common Stock 112307 I By LLC Series B Preferred Stock Common Stock 128839 I By LLC Series C Preferred Stock Common Stock 23572 I By LLC Series D Preferred Stock Common Stock 140932 I By LLC Series E-1 Preferred Stock Common Stock 138250 I By LLC Series E-2 Preferred Stock Common Stock 44801 I By LLC Series E-3 Preferred Stock Common Stock 39855 I By LLC Series F Preferred Stock Common Stock 209005 I By LLC Convertible Promissory Note Common Stock 874537.48 I By LLC 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 BioBrit, LLC, of which the Reporting Person is the managing member and has voting and investment power over the shares. The Reporting Person is the managing member of BioBrit, LLC, and has voting and investment power over the shares. The principal amount of the Convertible Promissory Note held by the Reporting Person is $874,537.48. 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. /s/ Greg Acosta, Attorney-in-fact 2019-07-24