Loriot et al9,10 led phase II and phase III trials (BLC2001) assessing erdafitinib in patients with metastatic or unresectable, locally advanced urothelial carcinoma that progressed after chemotherapy.11 Patients included in the studies had select FGFR3 mutation or FGFR2/3 fusion. This evidence concerns the gene FGFR2 and urothelial carcinoma.