Multiple strategies are adopted by GBM to induce immune-response suppression, such as the secretion of immunosuppressive factors, TGF-β derived from GBM cells, microglia and TAMs, IL-10, prostaglandin E-2 and immune checkpoint molecules such as programmed death-1 (PD1), stimulating the formation of Treg cells or suppressing cytotoxic T cells and DCs, impeding an antitumoral immune response [122,123]. This evidence concerns the gene TGFB1 and glioblastoma.