Taken together, radiation might counteract the immunosuppressive tumor microenvironment of GBM by increasing major histocompatibility complex (MHC) class I expression [82], enhancing the presentation of normally suppressed tumor-associated antigens while increasing the expression of proinflammatory cytokines, promoting dendritic cell maturation, and downregulating Fas ligand expression [83,84,85]. The gene discussed is FASLG; the disease is neoplasm.