PIK3CA and esophageal squamous cell carcinoma: These studies not only validated mutations of known cancer-related genes including TP53, CDKN2A, FAT1, NOTCH1, PIK3CA, EGFR, KMT2D, NFE2L2, but also identified several new recurrent alterations including ZNF750, AJUBA, FAM135B, TET2, XPO1 in ESCC.