SUCNR1 and pulmonary fibrosis: We established a BLM-induced pulmonary fibrosis model in WT mice and GPR91−/− mice. H&E staining and Masson’s staining of GPR91−/− mice treated with BLM showed significantly reduced pulmonary alveolitis and collagen deposition compared to BLM-induced WT mice (Fig. 8A–D).