In vitro and in vivo studies in bladder cancer have demonstrated that the FGFR3-TACC3 variant designated RT112 (after the bladder cancer cell line in which it was identified) is not only clinically relevant but that it also expresses a range of cellular behaviours that distinguish it from canonical FGFRs and imply distinct activation mechanisms31. This evidence concerns the gene FGFR3 and urinary bladder carcinoma.