Since it has been shown that high TAP1 expression resulted in better patient responses to anti-PD-1, anti-PD-L1, and anti-CTLA-4 immunotherapy in several cancers, increasing the TAP1 expression presumably could be an attractive form of improving the hitherto unsatisfactory results of the immune checkpoint blockade in glioma therapy [211,215]. This evidence concerns the gene PDCD1 and central nervous system cancer.