TNF and inflammatory bowel disease: Consistent with this is the demonstration that the inflamed gut of IBD patients contains a high number of antigen-presenting cells that display an activated phenotype, express high levels of TLRs, and respond to microbial components by producing huge amounts of inflammatory cytokines, such as IL-1β, IL-6, IL-18, and TNF, the expression of which correlates with the severity of inflammation (34).