FGFR1 and bladder transitional cell carcinoma: The cancers in which FGFR gene amplifications are most frequent include bladder urothelial carcinomas (FGFR1), squamous cell lung cancer (FGFR1), head and neck squamous cell cancer (FGFR1), uterine carcinosarcoma (FGFR3), breast adenocarcinoma (FGFR1), and gastric adenocarcinoma (FGFR2) (Tables 2 and 3, and Fig. 2).