DPP4 and inflammatory bowel disease: For one UC sample (UC2), we identified additional FP probe-enriched host proteases including cathepsin G, chymotrypsin-like elastase 2A and 2B, dipeptidyl peptidase 4, neutrophil elastase, and trypsin 1, lending support to the idea that aberrantly increased protease activity is associated with IBD (92, 104).