PRDM9 and cancer: One effective way to fight cancer is to inhibit methylation, and epigenetic drugs can have an impact on DNA methylation patterns.[69, 70] Several epigenetic drugs targeting histone methyltransferases and DNA methyltransferases are currently available for the treatment of many types of cancer.[71] For instance, Zebularine, Azacitidine, and Chaetocin have been broadly used in the clinical practice.[72] Epigenetic drugs are also involved in the application of neurological diseases, immunological diseases, and metabolic diseases.