IL17A and inflammatory bowel disease: Dextran sulfate sodium‐induced UC is associated with various clinical signs and the elevated expression of pro‐inflammatory cytokines, including IL‐6, IL‐17A, IL‐1β, and TNF‐α, which was consistent with the cytokine milieu observed in the mucosa of clinically active IBD patients (Eastaff‐Leung et al., 2010).