RET and neoplasm: Regorafenib is another oral multi-targeted kinase inhibitor that targets a number of pathways involved in tumor growth including tumor angiogenesis (VEGFR-1, -2, and -3, and TIE2), oncogenesis (KIT, RET, RAF-1, BRAF and BRAFV600E), and the tumor microenvironment [PDGFR and fibroblast growth factor receptor (FGFR)].