RAF1 and neoplasm: Sorafenib inhibits the activity of RAF proto-oncogene serine/threonine-protein kinase, B-Raf proto-oncogene, serine/threonine kinase, and kinases in the Rat sarcoma virus/Rapidly accelerated fibrosarcoma (Raf)/ Mitogen-activated protein kinase kinase (MEK)/Extracellular signal-regulated kinase (ERK) signaling pathway, resulting in decreased tumor cell proliferation.