PIK3CA and esophageal squamous cell carcinoma: In addition, the CNV overlapping genes between the eight PDCs and the 161 ESCC patients (recurrence ≥10%) contained MYC, FGF19, PTK2, CDKN2A, CDKN2B, CCND1, PLA2G1B, HSP90AA1, PIK3CA, FGF3, and FGF4 (Supplementary Fig. 4b).