Since ileitis (inflammation of ileum) and cobblestones are common in CD, we started examining mouse strains known for developing spontaneous ileitis, SAMP1/YitFc (SAMP) and C57BL/6J(B6)TNFdeltaARE/+ (TNFARE) (MP:0009482), and ileitis-free controls AKR/J (AKR) and B6 mice. This evidence concerns the gene TMEM201 and Crohn ileitis.