IL23A and Crohn disease: We compared expression of IL-23 in ileal biopsies from 219 patients with CD and non-inflamed controls in samples from the Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn’s Disease(RISK) study 26 (controls without ileal inflammation include 42 healthy donors and 61 patients with UC) (figure 4A).