Studies have shown that the process of DNA repair by tumor cells often depends on O6 methylguanine DNA methyltransferase (MGMT), suggesting that MDR caused by DNA repair can be reversed through function or expression inhibition to restore the efficacy of chemotherapeutic drugs, but there were few ideal results at present (Galluzzi et al., 2012; Housman et al., 2014; Hu et al., 2016). The gene discussed is MGMT; the disease is neoplasm.