TGFB1 and glioblastoma: In the tumor microenvironment, communication between different cell groups and the promotion of some neovascularization processes in GBM occur thanks to the presence of molecules such as Vascular Endothelial Growth Factor (VEGF), basic Fibroblast Growth Factor (bFGF), Transforming Growth Factor beta (TGF-β), and Matrix Metalloproteinases (MMPs), either as soluble isoforms or contained in extracellular microvesicles released by tumor cells [5,6].