TLR4 and inflammatory bowel disease: In inflammatory bowel disease, activated DCs could release the inflammatory cytokines such as IL-6, IL-12 and tumor necrosis factor (TNF-α) by up-regulating the pattern recognition receptors [Toll-like receptor (TLR) 2 and TLR4], MHC class II molecules, and costimulatory molecules (CD40 and CD86) [40].