FGF4 and esophageal squamous cell carcinoma: Amplifications of CCDN1, FGF19, FGF3, FGF4, SOX2, PI3KA, and MAP3K13 were observed more frequently in ESCC, whereas amplifications of ERBB2, KRAS, CCNE1, RARA, GATA4, and VEGFA were more common in EAC.