DNMT1 and pulmonary arterial hypertension: The DNMT inhibitor 5-aza-2′-deoxycytidine (Decitabine®), which is used in patients to treat myelodysplastic syndrome [39], restored SOD2 expression, suggesting that dysregulated DNMT activity may promote the excessive proliferation and impaired apoptosis of PASMCs in PAH [38].