In addition to inflammatory reactions, incremental evidence suggests that oxidative stress may impair the pulmonary vascular endothelium and induce the proliferation of vascular muscle cells in rat models of PAH.3 Moreover, increased oxidative stress was observed in PAH patients, while the reduction of oxidative stress was associated with an attenuation of the clinical symptoms.20 It was previously reported that ARC reduced oxidative stress in many diseases, in line with our finding that treatment with ARC significantly downregulated MDA levels and increased SOD activity (Fig. 5A and B). This evidence concerns the gene SOD1 and pulmonary arterial hypertension.