Moreover, Xie C et al. reported that depletion of mtDNA led to a hypermethylated E-cadherin promoter via DNA methylation by DNMT1 in prostate cancer and that hypermethylation reduced E-cadherin expression [55], and Cui et al. suggested that DNMT3A contributes to suppressing E-cadherin expression via DNA hypermethylation and the H3K9me2 and H3K27me3 histone modifications in gastric cancer [56]. Here, DNMT1 is linked to gastric cancer.