CD8A and glioma: Furthermore, it has been hypothesized that high levels of 2-Hydroxyglutarate (2-HG) in IDH mutated gliomas indirectly prevent the recruitment of effector T cells (CD8+ cytotoxic and killer T cells, CD4+ helper T cells) by lowering C-X-C motif chemokine ligand 9 (CXCL9) and C-X-C motif chemokine ligand 10 (CXCL10) levels, another hypothesis is that 2-HG accumulates and enters T cells altering CD8+ and CD4+ T-cell receptor (TCR) signaling pathways, thus resulting in impaired T cell anti-tumor immunity [33].