NOX4 and pulmonary arterial hypertension: The upregulation of ADAMTS8 expression in PASMCs downregulated AMPK, reduced the apoptosis rate (determined by an increase in the (B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax)) ratio) and enhanced NOX4-mediated ROS production and PASMC proliferation in patients and animal models within 4 weeks of chronic-hypoxia-induced PAH [183].