Fig 3 demonstrates the ROC curves for these two tests when comparing D-IBS subjects to IBD subjects. While both tests were effective at discriminating D-IBS subjects from the IBD group, the area-under-the-curve (AUC) for the diagnosis of D-IBS vs. IBD was higher for anti-CdtB than for anti-vinculin (0.81 and 0.62, respectively). In subgroup analysis, there appeared to be no difference based on the type of IBD (data not shown). The ROC curves for D-IBS compared to non-IBS, celiac subjects and healthy controls were also discriminatory (S1, S2, S3, S4 and S5 Figs). Here, VCL is linked to inflammatory bowel disease.