Sorafenib, approved in 2008, inhibits multiple growth tyrosine kinase receptors (PDGFRs, VEGFRs, c-KIT, and RET) and their downstream tyrosine kinase cascades (Ras, Raf, Mek, and Erk) in both tumor cells and endothelial cells [202,203,204]. The gene discussed is RAF1; the disease is neoplasm.