FLT3 and renal cell carcinoma: The orally available anti-angiogenic TKI, sorafenib is a multi-targeted inhibitor of raf-kinase, VEGFR1, VEGFR2, VEGFR3, PDGFR-β, Flt3 and c-kit, which has been approved in the treatment of both advanced renal cell carcinoma and hepatocelullar carcinoma.