FLT1 and neoplasm: Regorafenib is an oral multikinase inhibitor that blocks the activity of multiple protein kinases, including those involved in the regulation of tumor angiogenesis (VEGFR1, 2, and 3, and TIE‐2), oncogenesis (KIT, RET, RAF‐1, BRAF, and BRAFV600E), and the tumor microenvironment (PDGFR and FGFR) 1, 2, 3.