IL17A and inflammatory bowel disease: Similarly, a large real-world retrospective longitudinal cohort study of the incidence of IBD among patients with CIDs treated with IL-17 blockers or PDE4 inhibitors found that treatment with IL-17 antagonists was associated with more than 3-fold higher odds of having IBD relative to patients naïve to biologics and patients treated with biologics not indicated for the treatment of IBD [38].