TNF and inflammatory bowel disease: Proinflammatory cytokines, especially tumor necrosis factor (TNF), are produced mainly by activated immune cells in inflamed mucosa during the process of IBD, and those proinflammatory cytokines further activate immune cells, as the feedback, to produce toxic molecules including super oxygen products, chemokines, proteinases, and cytokines which result in tissue damage and inflammation development [2, 3].