Previous reports showed that inflammatory bowel disease is characterized by the secretion of proinflammatory cytokines (TNF, IFN-γ, IL-6, and IL-12) and anti-inflammatory cytokines (IL-10, TGFβ, and IL-35) in local tissues (20, 21), In particular, CD patients reportedly demonstrate an increased production of IL-12, IL-23, IFN-γ, and IL-17 (20). This evidence concerns the gene IL17A and inflammatory bowel disease.