Background: Serum dipeptidyl peptidase 4 (DPP-4) has drawn particular interest as a biomarker in inflammatory bowel disease (IBD), as this protease inactivates several peptides that participate in the inflammatory cascade. Methods: Two prospectively recruited cohorts consisting of 195 patients (101 had Crohn’s disease [CD] and 94 had ulcerative colitis [UC]) were evaluated using clinical indexes and followed up...