Moreover, the Enhancer of Zeste 2 Polycomb Repressive Complex 2 Subunit (EZH2), the PcG protein in the PRC2/3 which catalyzes H3K27me3 trimethylation, has been overexpressed in cancer and was associated with tumor progression and prognosis in prostate, breast, melanoma, endometrium, and bladder and gastric cancers [48,49,50,51]. This evidence concerns the gene EZH2 and gastric cancer.