TNF and irritable bowel syndrome: A variety of cytokines, namely, IL-1β, TNF-α, and IL-6 mediate intestinal inflammation in IBD, while relevant biologic agents have been developed such as anti-TNF drugs infliximab, IL-12/IL-23p40 antibody ustekinumab, integrin α4/β7 heterodimer monoclonal antibody vedolizumab, but their current widespread use is limited by several complex reasons, thus the inflammatory process in IBD needs further elucidation (2).