MPO and inflammatory bowel disease: In comparison with the control group (PBS + water), the mice in the TNBS- or oxazolone-treated groups (PBS + TNBS or PBS + OXA) showed a series of symptoms of IBD, such as weight loss, colon shortening, and damage, together with enhanced myeloperoxidase (MPO) activity, indicating that the IBD model was successfully established in mice (Supplementary Figs. 14 and 15).