VEGFA and glioblastoma: Glioblastoma is a highly vascularized neoplasm in which angiogenesis is supposed to be triggered by the expression of the hypoxia-inducible factor (HIF-1) and by vascular endothelial growth factor (VEGF) secreted by the tumor cells [31] and the effects are further enhanced by a variety of pro-angiogenic cytokines.