These experiments showed that engraftment of DKO mice with IL10−/− BMMCs ameliorated colitis in a similar manner to WT BMMCs (IL10−/− mean colitis score 3.1 ± 0.3; DKO colitis score 5.3 ± 0.8; and DKO-RIL10−/− colitis score 2.2 ± 0.6; p < 0.005), overall indicating that mast cells' protective effects are via a mechanism independent of IL10 secretion (Figure 2). This evidence concerns the gene IL10 and colitis.