EZH2 and cancer: In gastric cancers, high levels of enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), a writer of H3K27me3, results in gene repression, whereas the epigenetic mark levels have been reduced when the core components of the polycomb complex are reduced, indicating the contextual nature of epigenetic marks in the heterogenous cancer background [26].