VEGFA and glioblastoma: In general, the tumor bulk in GBM can be schematically divided into three major moieties: (i) the tumor core where the normal tissue is completely replaced by neoplastic cells and an enhanced permeability of the blood vessels is present, (ii) the angiogenic forehead which is mainly driven by VEGF expression, (iii) the brain adjacent to tumor, where the invading tumor cells infiltrate into normal brain tissue and the vasculature remains intact (Woodworth et al., 2014; van Tellingen et al., 2015; Dréan et al., 2016).