VEGFA and neoplasm: Hypoxia stimulates HIF signaling pathways and, in particular, activates HIF-1α [31], which plays a synergistic role in the expression of downstream genes (such as VEGF, p53, and erythropoietin (EPO)) and counteracts anti-proliferative and pro-apoptotic genes (such as NIX, BNIP3, and IGFBP3), thus significantly promoting tumor growth [34, 35].