Sorafenib is an orally active multikinase inhibitor that blocks intracellular kinases in the Raf/MEK/ERK pathway that are involved in tumor proliferation, such as Raf-1, as well as those promoting angiogenesis, including VEGFR-2, VEGFR-3, FLT, PDGFR-b, FMA, RET, and c-KIT. The gene discussed is RAF1; the disease is neoplasm.