Guercio et al. evaluated patients with UC for FGFR3 alterations predictive of Erdafitinib sensitivity finding 14% of patients with MIBC, 39% of patients with NMIBC, 43% of patients with localized upper tract urothelial carcinoma (UTUC), and 26% of patients with metastatic disease harbored these mutations. The gene discussed is FGFR3; the disease is metastatic neoplasm.