VEGFA and glioblastoma: During (glial) brain tumor progression, vascular dysfunction is partially mediated via angiogenic factors including VEGF-VEGFR (17, 109–111), and blocking VEGF-VEGFR signaling results in transient normalization of the immature and leaky brain tumor vasculature and leads to survival benefits in patients with newly diagnosed as well as recurrent GBM (17, 112, 113).