FGFR3 and cancer: The genes encoding the fibroblast growth factor receptors (FGFR1, FGFR2, FGFR3, and FGFR4), mapping to different chromosomes, have been increasingly recognized to be parts of gene fusions involving diverse fusion partners and occurring across a variety of common and rare cancer types in different organs, with generally low but entity-dependent frequencies [1–3].