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). The gene discussed is FGFR1; the disease is uterine carcinosarcoma.