WEE1 and neoplasm: 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).