IL17A and Cowden disease: Likewise, although IL-17A is an active cytokine in gut inflammation, the clinical outcome of anti-IL-17A therapy (secukinumab and ixekizumab, anti-IL-17A mAbs) in CD patients is not favorable [83], and a study based on IL-17a-/- mice found that blockade of IL-17A may cause IL-6 upregulation and RORγt+ ILC recruitment during chronic colitis, leading to elevated IL-22 and even worsened disease [84].