HMOX1 and idiopathic pulmonary fibrosis: We did not observe significant differences in antioxidant genes between IPF patients and controls, although the oxidant-sensitive transcription factor NRF2 (p = 0.19), as well as CAT (p = 0.23) and SOD2 (p = 0.21), appeared to be slightly downregulated in IPF patients, whereas HO-1 and SOD1 tended to be slightly upregulated (Figure 3C).