A cytokine whose expression has been found correlated with those of IL-8 is TNF-α; in fact, TNF-α is a pleiotropic pro-inflammatory cytokine implicated in a wide range of cellular processes, thus being an inflammation key mediator and it was seen to be highly expressed in IBD, being produced by both T helper 1 (Th1) and Th2 lymphocytes as well as by macrophages [68,71]. The gene discussed is CXCL8; the disease is inflammatory bowel disease.