Activating FGFR3 mutations have been identified in 10–60% of urothelial carcinomas, predominately in low-grade tumours.21 The most frequent FGFR3 SNVs were R248C and S249C occurring in the extracellular domain, as well as G370C and Y373C occurring in the transmembrane domain.1 The resulting cysteine residues from these mutations lead to ligand-independent dimerisation of the receptor.22 In addition, FGFR3 mutations have been reported to occur in 5% of cervical carcinomas.23 Here, FGFR3 is linked to urothelial carcinoma.