Serum CCL20 levels did not demonstrate diagnostic ability to distinguish active disease from disease in remission for Crohn’s disease at a cutoff value of 5.64 pg/mL or higher [AUC (95% CI): 0.57 (0.45, 0.70), p = 0.23; sensitivity: 0.42 (0.23, 0.63), specificity: 0.74 (0.66, 0.81)] and for ulcerative colitis at a cutoff value of 2.86 pg/mL or higher [AUC (95% CI): 0.51 (0.38, 0.64), p = 0.16; sensitivity: 0.62 (0.46, 0.76), specificity: 0.47 (0.31, 0.64)]. This evidence concerns the gene CCL20 and ulcerative colitis.