Regorafenib potently blocks several protein kinases that are involved in tumor angiogenesis (VEGFRs 1–3), oncogenesis (BRAF, RAF, RET, KIT), metastasis (FGFR, PDGFR, VEGFR3) and tumor microenvironment (TME) signaling (Tie2, CSF1R). This evidence concerns the gene RET and neoplasm.