Significantly increased levels of PAI-1 were detected in the sera of the patients with IBD (P<0.0001), and an AUC value of 82.78% (95% confidence interval (CI) 71.89 to 93.67%) was achieved in the discrimination between the IBD patients and controls (Figure 7D and E, Table S2). The gene discussed is SERPINE1; the disease is inflammatory bowel disease.