In the present study, we found S100A4 increased in lung tissues of BLM-induced PF mice and TGF-β1-treated HEF1 cells (Figures 2A, B), blocking S100A4 expression by siRNA exhibited anti-fibrosis effects (Figures 3A, B) or inhibiting STAT3 phosphorylation with a small molecule inhibitor static (Figures 4B, C), as well as MET (Figures 5, 6). Here, STAT3 is linked to pemphigus foliaceus.