These cell lines were derived from human bladder tumors, and they endogenously express a mutated activated form of FGFR3 (FGFR3‐Y375C, the second most frequent mutation in bladder tumors) and the FGFR3‐TACC3 fusion protein (the most frequent FGFR3 fusion protein in bladder tumors), respectively. This evidence concerns the gene FGFR3 and urinary bladder neoplasm.