VEGFA and neoplasm: In tumor cells, different transcription factors, such as HIF, can induce the production of pro-angiogenic factors, such as VEGF and platelet-derived growth factor (PDGF), thereby stimulating the de novo generation of blood vessels within the tumor and leading to the formation of a unique tumor vasculature, also referred to as the tumor-associated vasculature system (25) (Figure 2).