It is known that patients with IBD have altered levels of cytokines, so researchers have focused on finding an association between polymorphisms of these cytokines and the relationship between promoters such as tumor necrosis factor-alpha (TNFα) and interleukin 10 (IL-10), as well as the relationships found between IL-1 and its receptor or between the IL-6 and the IL-23 receptor [28]. The gene discussed is TNF; the disease is irritable bowel syndrome.