Studies have shown that the expression of IL-17A and IL-22 was increased in the airways of patients with COPD and that IL-22 can promote airway inflammation by acting in synergy with IL-17A.26,27 These data suggest that inhibition of Th17-related cytokines might be a useful strategy for COPD treatment but, so far, no studies with anti-IL-17 or anti-IL-17 receptor antibodies, which are clinically effective in psoriasis and inflammatory bowel disease, have been reported in patients with COPD. This evidence concerns the gene IL17A and inflammatory bowel disease.