Sorafenib (BAY 43-9006) is an orally active kinase inhibitor that exerts broad-spectrum anticancer efficacy in vitro and in vivo via targeting b-Raf, c-Raf (Raf-1), as well as several receptor tyrosine kinases involved in neovascularization and tumor progression, including vascular endothelial growth factor receptors 2/3 (VEGFR-2/Flk-1/KDR, VEGFR-3), platelet-derived growth factor receptor-beta (PDGFR-ß), Flt-3, c-KIT, FGFR-1 (Flt-2) and RET.