The results of the western blot analysis show that in the BLM group, the levels of NOX4, hypoxia‐inducible factor ‐1 alpha (HIF‐1α), vascular endothelial growth factor (VEGF), TGF‐β1, and Collagen I were substantially elevated in the lung tissues of the mice with PF as compared with the CON group, while FA significantly reversed these levels compared to the BLM group (Figure 6B). This evidence concerns the gene NOX4 and pemphigus foliaceus.