FLT1 and neoplasm: By targeting multiple signaling pathways, including VEGF, fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), FMS-like tyrosine kinase (FLT), rearranged during transfection (RET), and c-Kit, AA-TKIs exert anti-tumor effects via the induction of tumor vascular regression and the suppression of angiogenesis (36, 37).