Murine models of chronic IBD, including colitis induced by the transfer of naive CD4+CD45RBhi T cells into recombinase activating gene deficient (Rag−/−) hosts and bacterially driven intestinal inflammation in the context of IL-10 deficiency, can be effectively prevented by treatment with IFN-γ neutralizing antibody 34, 35. The gene discussed is IL10; the disease is colitis.