RET and neoplasm: Regorafenib can inhibit a variety of kinases involved in angiogenesis (including lymphangiogenesis), cell proliferation, and tumor growth as well as the tumor microenvironment, mainly including VEGFR1∼3 (angiogenesis), KIT, RET (tumor formation), PDGFR-β, and FGFR (tumor microenvironment), thereby controlling tumor growth and delaying disease progression [23].