In a rat lung fibrosis model induced by BLM, dexamethasone (positive control group) and rutin significantly reduced the protein expression rates of fibrosis biomarkers (a-SMA, collagen I and collagen III) and TGF-β1, improved bleeding, thickening of alveolar septa, infiltration of alveolar wall cells, and necrosis of alveolar tissue. The gene discussed is TGFB1; the disease is pulmonary fibrosis.