In a separate retrospective analysis of 274,694 patient tumour samples, genomic alterations in FGFR1–3 (FGFR4 was not assessed) were detected by next-generation sequencing in 2.3% of patient specimens, of which 64.8% were SNVs and 35.9% were rearrangements.12 In both studies, almost all tumour types were found to have FGFR alterations, but those with the highest alteration frequency included urothelial cancer, cholangiocarcinoma, endometrial cancer, squamous lung cancers, breast cancer and cervical cancer.3,12 In this section, we catalogue the diversity of FGFR SNVs, gene fusions and CNAs. The gene discussed is FGFR4; the disease is breast carcinoma.