TGFB1 and glioblastoma: Because the microenvironment of GBM is highly immunosuppressive [35], we have then analyzed the gene expression patterns of the two risk groups and found that the high risk group exhibits significantly increased expression of classical immunosuppressive factors such as IL10, TGF-β, PDL1, and FASL and many immunosuppressive cell markers related to immunosuppressive cells such as tumor-associated macrophage M2, Tregs, and MDSC.