FLT3 and renal cell carcinoma: Sorafenib is an oral multikinase inhibitor, approved for the treatment of advanced renal cell carcinoma and HCC by the U.S. Food and Drug Administration and the European Medicine Agency, targeting on Raf, epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), FMS-like tyrosine kinase-3 (Flt-3) and c-kit [9].