KDR and neoplasm: Sorafenib can inhibit tumor cell proliferation and angiogenesis, thereby inducing cancer cell apoptosis, which not only blocks the Ras/MEK/ERK-mediated cell signaling pathway but also blocks tumor angiogenesis, by inhibiting kinases such as vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) (1, 6).