In the inflamed gut of IBD patients, there is also a reduced expression of aryl hydrocarbon receptor (AHR) (61), the activation of which in DC leads to a reduced expression of activation markers (i.e. CD80, CD83, and CD86) and diminished production of inflammatory cytokines (i.e., IL-1β, IL-23, and IL-12). The gene discussed is IL23A; the disease is inflammatory bowel disease.