CHIR-258, a potent inhibitor of Flt3 (fms-like tyrosine kinase receptor-3), c-Kit tyrosine kinase, and fibroblast growth factor receptor 3 (FGFR3), prevented cell growth of FGFR3-positive human multiple myeloma cell lines and augmented their sensitivity to GC-induced apoptosis [122]. This evidence concerns the gene FGFR3 and plasma cell myeloma.