Chaetocin is primarily known for its role as a potent inhibitor of histone methyltransferases, particularly those in the SUV39 family. This makes it a valuable tool in epigenetic research, where it is used to study gene expression regulation through histone modification. By blocking lysine methylation on histone H3, chaetocin induces changes in chromatin structure, leading to the reactivation of silenced tumor suppressor genes. Due to its impact on epigenetic pathways, chaetocin has shown promising anti-cancer activity in various preclinical models. It has demonstrated cytotoxic effects against multiple cancer cell lines, including leukemia, myeloma, and solid tumors, often by promoting oxidative stress and disrupting redox balance within cells. Its ability to generate reactive oxygen species (ROS) contributes to DNA damage and apoptosis in malignant cells. In addition to oncology, chaetocin is being explored for its potential in overcoming drug resistance in cancer therapy, as it can sensitize resistant cells to conventional treatments. While still in the research phase and not used clinically, chaetocin serves as a lead compound for developing new epigenetic therapies targeting histone methylation.