Activation of the immune system contributes to creating an immunosuppressive microenvironment in GBM [33], which consists of the production and release of immunosuppressive cytokines and chemokines, such as transforming growth factor-β (TGF-β), interleukin 10 (IL-10), prostaglandin E2 (PGE2), and many immune cells, such as immunosuppressive natural killer (NKT) cells, regulatory T/B cells (T/B-reg), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSC) [34,35]. This evidence concerns the gene TGFB1 and neoplasm.