UNC1999 is primarily utilized in the field of biomedical research as a potent and selective inhibitor of EZH2, an enzyme involved in gene regulation through histone methylation. Its application is significant in studying the role of EZH2 in various cancers, particularly lymphoma and leukemia, where EZH2 overexpression is often observed. Researchers employ UNC1999 to investigate the therapeutic potential of EZH2 inhibition in cancer treatment, as it can suppress tumor growth by reactivating silenced tumor suppressor genes. Additionally, it serves as a valuable tool in epigenetics research, helping to elucidate the mechanisms of chromatin remodeling and gene expression control. Its selectivity and efficacy make it a key compound in preclinical studies aimed at developing targeted cancer therapies.