DPP4 and Crohn disease: In inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease (CD), some inverse correlations have been reported between the enzymatic activity of DPP-4, the clinical activity score of the disease and inflammatory markers (alpha-1-acid glycoprotein) and PCR [13], whereas when analyzing only the population with CD in its active phase, the levels of DPP-4 are decreased in plasma and tissue, suggesting the possible use of this biomarker [14].