EPZ031686 is primarily utilized in research settings as a potent and selective inhibitor of the EZH2 enzyme, which plays a critical role in gene regulation through histone methylation. Its application is significant in the study of cancers, particularly those driven by EZH2 overexpression or mutations, such as certain types of lymphomas and solid tumors. By inhibiting EZH2, it helps researchers understand the epigenetic mechanisms underlying tumorigenesis and evaluate potential therapeutic strategies. Additionally, it is used in preclinical studies to assess the efficacy of targeting EZH2 in cancer treatment and to explore its impact on other diseases influenced by epigenetic dysregulation.