There are two major types of inflammatory bowel disease, Crohn disease and ulcerative colitis. Conflicting reports have indicated the soluble factor IL-22 can have both IBD promoting and IBD controlling effects. A new study has, however, now indicated that local delivery of the Il-22 gene ameliorates disease in a mouse model of UC, leading to the suggestion that individuals with UC might benefit from local delivery of the IL-22 gene to their intestines.