Neuroendocrine tumors are highly vascular tumors and overexpression of proangiogenic molecules and their receptors such as vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR), platelet-derived growth factor (PDGF)/PDGFR, fibroblast growth factor (FGF)/FGFR, and epithelial growth factor (EGF)/EGFR have been reported (55, 56). Here, VEGFA is linked to vascular neoplasm.