TNF and inflammatory bowel disease: Despite intense interest, the pathogenesis of IBD still remains poorly understood; the imbalance between pro-inflammatory cytokines, such as TNF-α, IFN-γ, IL-1β, IL-6 and IL-12, and anti-inflammatory cytokines, such as IL-4, IL-10 and IL-11, is thought to play a pivotal role in modulating gut inflammation [32].