Alternatively, C57 congenic models, including SHIP-/- (B6.129S6(C)-Inpp5dtm1.1Wgk/J) mice, which develop segmented, transmural ileitis due to perturbations in intestinal T cell immunity, present an opportunity to study Itln1 in isolation (60, 61). The gene discussed is ITLN1; the disease is Crohn ileitis.