Despite the fact that the FDA-approved nivolumab targeting programmed cell death protein 1 (PD-1) and Ipilimumab targeting CTLA-4 have displayed clinical therapeutic superiority compared to conventional therapies in multiple types of cancers (13–16), the combination of nivolumab and Ipilimumab shows no significant effects on recurrent glioblastoma (17, 18). This evidence concerns the gene PDCD1 and cancer.