TNF and inflammatory bowel disease: As a key cell population contributing to mucosal damage in IBD, IMF of patients with UC induced by inflammatory mediators (TNF-α and LPS) can stimulate miR-155 levels, and miR-155 also induces the production of cytokines (IL-6 and IL-8), which leads to the transmitting inflammation, and then aggravates the intestinal epithelium inflammation (3).