INPP5D and Crohn ileitis: SHIP-1−/− mice with ileitis, which was diagnosed at necropsy, were observed to have similar body weights to ileitis-free SHIP-1−/− mice by 12 weeks of age (Fig. 1B), and while their spleen weight was not significantly different (Fig. 1C), they exhibited a significantly increased spleen weight to body weight ratio (Fig. 1D) and an increased shortening of the small intestine (Fig. 1E).