Accordingly, patients with IBS showed increased levels of pro-inflammatory cytokines including interleukin (IL)-1b, tumour necrosis factor-alpha (TNFα), IL-6 and IL-8, and reduced levels of anti-inflammatory cytokines such as IL-10 [11], IL-5 and IL-13 [10]. This evidence concerns the gene CXCL8 and irritable bowel syndrome.