DNMT1 and cancer: These PTMs lead to gene repression/activation, respectively, during the cell cycle and development.81 DNMT1 dysregulation is associated with the silencing of tumor-suppressor genes,80 and DNMT1 was found to be overexpressed and associated with poor prognosis in prostate,82 breast,83 colon,84 gastric,85 bladder86 and lung87 cancers.