Figure 7A shows that CFH, HDC, and STEAP1 (all p < 0.001) were significantly overexpressed in IPF, with AUROC of 0.73 (95% CI = 0.62–0.85), 0.77 (95% CI = 0.66–0.88), and 0.75 (95% CI = 0.68–0.83), respectively (Figures 7D, F). However, the expressions of NUDT16 (p = 0.05) and FMO5 (p < 0.001) were significantly lower in the IPF group compared to controls. The AUROC for these genes were 0.63 (95% CI = 0.55–0.71) and 0.79 (95% CI = 0.70–0.87) (Figures 7B, C), which is consistent with the expression we obtained earlier. The gene discussed is HDC; the disease is idiopathic pulmonary fibrosis.