FGFR3 and urinary bladder cancer: By studying the effects of FGFR3 mutations using OH‐BBN‐induced, genetically engineered mouse models of invasive bladder cancer, we report three significant findings: firstly, in the presence of mutationally activated FGFR3 S249C, there was an increased number of mice that developed bladder tumours and the tumour phenotype was more advanced (Figure 2).