PIK3CA and esophageal squamous cell carcinoma: Recapitulating previous reports, we confirmed mutations in 12 genes, including MLL2, FAT1, PIK3CA, EP300, ZNF750, CREBBP, NOTCH3, PTCH1, RB1, KDM6A, TGFBR2 and PTEN. Furthermore, we identified two novel mutated genes, CUL3 and RBPJ, in ESCC (Fig. 2 and Supplementary Data 4).