Preclinical studies have demonstrated that human bladder cancer cell lines with FGFR3 mutations and fusions are sensitive to FGFR inhibitors such as BGJ398 (Infigratinib, Novartis), PD173074 (Pfizer) and erdafitinib (Balversa, Janssen) [17, 19–22], thereby forming the basis for clinical trials of FGFR inhibitors in patients with metastatic urothelial cancer. The gene discussed is FGFR3; the disease is urinary bladder cancer.