We further screened significant events by using a t-test and found that most of the infiltrating immune cell types upregulated in GBM were related to immune activation, including CD4 T cells, CD8 T cells, dendritic cells, natural killer cells, and Type 1 T helper cells, although the repressive regulatory T cells were upregulated in the same group of patients as well (Figure 3B). This evidence concerns the gene CD8A and glioblastoma.