A recent study found that EZH2, in hepatoma cells, can suppress PD-L1 expression by directly upregulating H3K27me3 levels on the promoters of CD274, which encodes PD-L1 and interferon regulatory factor 1 (IRF1), an essential transcription factor for PD-L1 expression [79]. This evidence concerns the gene IRF1 and hepatocellular carcinoma.