In the acute phase of DSS-induced colitis when the colonic epithelial barrier is disrupted by DSS, macrophages are stimulated to polarize the M1 phenotype and eliminate pathogens by producing nitric oxide and secreting large amounts of proinflammatory cytokines, such as tumor necrosis factor (TNF)-α, IL-1β, and IL-6, but cause direct colonic mucosal injury and exacerbate colitis [58,59]. This evidence concerns the gene TNF and colitis.