SFN treatment of bleomycin-induced pulmonary fibrosis attenuates fibrosis, apoptosis and lung oxidative stress by increasing the expression of antioxidant enzymes, NQO1, HO-1, SOD and catalase, via upregulation of Nrf2 gene expression (Yan et al., 2017). This evidence concerns the gene SOD1 and pulmonary fibrosis.