EPZ005687 is a selective inhibitor of the enhancer of zeste homolog 2 (EZH2), which is a histone methyltransferase involved in gene silencing. It is primarily used in epigenetic research to study the role of EZH2 in cancer development, particularly in lymphomas and other malignancies with dysregulated EZH2 activity. By inhibiting EZH2, EPZ005687 reduces the methylation of histone H3 at lysine 27 (H3K27me3), leading to reactivation of tumor suppressor genes. This compound serves as a valuable tool for investigating epigenetic mechanisms and has shown potential in preclinical studies for the treatment of cancers driven by EZH2 overexpression or mutations. It is not used clinically but supports the development of targeted epigenetic therapies.