Earlier, another group has analyzed epigenetic modifications of PDCD1 (PD1), CD274 (PD-L1), and CTLA4 in NSCLC tissues, and found that decreased methylation of regulatory regions in CTLA 4 and PDCD1 (PD1) genes correlated with increased expression of these ICM in the TME of NSCLC [212], suggesting the utility of these epigenetic modifications as potential diagnostic/prognostic biomarkers and/or therapeutic targets in the cancer setting. This evidence concerns the gene PDCD1 and cancer.