RET and neoplasm: Regorafenib is a multikinase inhibitor that blocks the activity of protein kinases of several receptors (VEGFR1, VEGFR2, VEGFR3, TIE2, KIT, RET, RAF1, BRAF, PDGFR, and FGFR) involved in various signaling pathways regulating angiogenesis, tumor growth, and tumor microenvironment [88].