Il10−/− mice with mast cell deficiency due to the KitW-sh/KitW-sh mutation (DKO mice), DKO mice reconstituted with WT BMMC, and DKO mice reconstituted with Il10−/− BMMC also developed moderate to severe colitis when exposed to piroxicam, with severity that statistically did not differ from that seen in mast cell-sufficient Il10−/− mice (p = 0.14, 0.34, and 0.93, respectively; Figure 2). The gene discussed is IL10; the disease is colitis.