TNF and Cowden disease: However, our 100-day study shows that chronic exposure to a low dose of E171 moderately increases the mucosal content of IL-6, TNF-α, IL-8 and IL-10 in the rat colon without triggering significant changes in other inflammatory cytokines such as IFN-γ, which normally flares in rodent models of acute colitis43, 44 and in CD patients41, 45.