The malondialdehyde (MDA) level was significantly decreased while the levels of antioxidant superoxide dismutase (SOD) and glutathione (GSH) were increased after upregulating NKD1 in PAs of MCT-treated mice (Supplementary Figure 3), suggesting that NKD1 could alleviate oxidative stress in mouse PAH model. This evidence concerns the gene SOD1 and pulmonary arterial hypertension.