Studies in non-small cell lung cancer and renal cell carcinoma have demonstrated a positive correlation between CD8+ T cell infiltration and tumor grade, potentially related to the increased number of tumor-associated neo-antigens in dedifferentiated cancers20,21, A similar mechanism may be occurring in GBM, as the mesenchymal subtype of GBM, which carries the worst prognosis, and hypermutated tumors are both associated with increased lymphocyte infiltration11,14. Here, CD8A is linked to glioblastoma.