Our results indicate that DSS treated Sigirr −/− mice, which are deficient in SIGIRR/in interleukin-1 receptor, serve as a good model for CD, where inflammation/infection occurs in the small intestine and Peyer’s patches, in comparison to the other IBD in vivo model, where inflammation occurs only in the colon. The gene discussed is SIGIRR; the disease is inflammatory bowel disease.