MMP7 and pulmonary fibrosis: Compared with the MMP-7 levels and HYP content in the control group, those in the BLM-induced lung fibrosis rats in the model group were found to have increased significantly by 109.44% (from 18.53 ± 0.89 to 38.81 ± 3.59 mg/g protein, p < 0.05) and 257% (from 0.59 ± 0.06 to 2.10 ± 0.40 mg/g wet tissue, p < 0.05), respectively.