Combination therapy with a DNMT inhibitor and a histone deacetylase inhibitor has shown encouraging results.34,35 In addition, the synergistic effects of DNMT inhibitors and chemotherapeutic agents have also been observed.36 However, the high toxicity of DNMT inhibitors for long-term use is a main factor limiting their clinical application.37 In the past 10 years, RNA molecule has become one of the most promising therapeutic targets of cancers. The gene discussed is DNMT1; the disease is cancer.