To explain this patient's robust outlier response to pazopanib, we genomically analysed the tumour using targeted mutation profiling (Foundation Medicine, Cambridge, MA, USA), which revealed a sole activating mutation in FGFR3 (S249C). The sole presence of a mechanistically confirmed activating mutation and potent response to pazopanib is consistent with the hypothesis that FGFR3 was a molecular driver in this patient with UC...