(A) Quantitative PCR was used to evaluate the relative expression of candidate genes (ANXA3, STX11, THBS2, MMP1, MMP9, MMP7, MMP10, SPP1, COL1A1, ITGB8, IGF1) in human normal lung tissues (n = 3) and IPF lung tissues (n = 3), and the relative quantification of the expression of the candidate genes was measured using glyseraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA as an internal control. Data are presented as mean ± SEM (n = 3; *** p < 0.001, **** p < 0.0001; by two-way ANOVA with Duncan’s post hoc test). (B) The expression of MMP7, IGF1, SPP1, MMP9, and ITGB8 in human normal lung tissues (n = 3) and IPF lung tissues (n = 3) was determined by immunohistochemistry (scale bars: left panels = 100 μm, right panels = 50 μm). The DAB Substrate System (DAKO) was used to reveal the immunohistochemical staining; the positive areas in each image were analyzed by Image J software; the percentages of MMP7, IGF1, SPP1, MMP9, and ITGB8 areas were quantified (*** p < 0.001, **** p < 0.0001).