CD8A and oligodendroglioma: Although the median frequency of CD3+/CD8+ cytotoxic T cells (Figure 5B) was marginally increased in the blood of patients with oligodendroglioma, astrocytoma, and GBM (median frequencies of 25.2%, 25.1%, and 19.4%, respectively), no significant differences were observed when compared to the healthy controls (median frequency of 18.4%).