In this experiment, the expression of TLR4 in mouse lung tissue increased significantly 72 hours after LPS treatment and was accompanied by increased expression of α-SMA, type I procollagen, and PICP; moreover, the degree of pulmonary fibrosis became intense 4 weeks after LPS challenge (Figures 1, 2, 3). The gene discussed is COL1A2; the disease is pulmonary fibrosis.