Immune responses in GBM is characterized by low peripheral lymphocyte counts, impaired mitogen-induced responses of peripheral mononuclear cells, and accumulation of CD8+ suppressor T cells and CD4+CD25+FoxP3+Treg cells, which have been reported to play a crucial role in cancer immune surveillance and defense by inducing cytotoxic cell death and inhibiting glioma cell proliferation and migration of glioma (18–20). This evidence concerns the gene CD8A and central nervous system cancer.