It was observed in human glioma cells that hypoxia induces PD-L1 upregulation in an HIF-1α-dependent manner, and it was further found in a murine glioma model that the combination of HIF-1α inhibitor and anti-PD-L1 antibody can improve the activation of DCs and CD8+ T-cells (123). This evidence concerns the gene CD8A and central nervous system cancer.