PIK3CA and colorectal carcinoma: As shown in Fig. 4B, a Pten p.335X stop gain mutation at 14% VAF in an HGSC GEMMs was the only mutation directly prioritized as functionally significant; however, three additional GEMM samples (one each HGSC, EC, and colorectal carcinoma) each harbored a single prioritized mutation, representing the human equivalent of PIK3CA p.E545K (HGSOC; Pik3ca p.E545K, 55% VAF), SMAD4 p.R361G (colorectal carcinoma; Smad4 p.R360G; 19% VAF), and SMAD4 p.E526Q (EC; Smad4 p.E525Q 10% VAF; Supplementary Table S5).