IL22 and Crohn disease: Paneth cells and their antimicrobial products (α-defensins, lysozyme, etc.)play a critical role in small intestinal host defense to injury or infection, and their dysregulation constitutes a pathogenic factor for Crohn’s Disease.13–15 Crohn’s patients have Paneth cell abnormalities and elevated levels of IL-22 in inflamed tissue.14,16,17 However, how IL-22 regulates Paneth cell function remains poorly understood.