FGFR1 and esophageal squamous cell carcinoma: A total of 21 squamous cell carcinomas and 4 adenocarcinomas harbored FGFR1 copy number increases that did not reach the predefined threshold for amplification, including 15 cancers with polyploidy of chromosome 8 (15 ESCC) and 10 cancers with FGFR1 gains (6 ESCC and 4 EADC).