SOD3 and idiopathic pulmonary arterial hypertension: The expression/activity of SOD3 in the lung from human idiopathic pulmonary arterial hypertension was reduced, and this downregulation could be reversed by the treatment of PASMCs with class I HDAC inhibitors or HDAC3 siRNA [217], suggesting that histone deacetylation negatively regulates SOD3 expression.