In the parents, as expected, the fold-difference in colon weight/colon length ratio (Fig. 5b), spleen weight (Fig. 5c) and colonic MPO (Fig. 5d), and the 1/fold-change ratio of the percentage of initial body weight (Fig. 5e) in PepT1−/− compared with WT mice were less than 1, indicating that DSS-induced colitis was less severe in PepT1−/− mice than in WT mice. The gene discussed is MPO; the disease is colitis.