CD274 and oral cavity squamous cell carcinoma: Epigenome-wide DNA methylation profiling of 87 Gingivo-buccal oral squamous cell carcinoma (OSCC-GB) patients reported upregulation of PD-L1 and CD80 due to significant promoter hypomethylation, thus inhibiting apoptosis of OSCC-GB cells due to the immunosuppressive characteristics of PD-L1/PD-1 interactions [246].