VEGFA and glioblastoma: The following pro‐angiogenic proteins were identified in exosomes originating from glioblastoma cells: angiopoietin, angiogenin, fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), IL‐6 and IL‐8, and the tissue MMP inhibitors TIMP‐1 and TIMP‐2.