Likewise, in asthma patients, while serum IL‐22 levels are elevated and correlate positively with disease severity (41, 42), levels in bronchoalveolar lavage fluid correlate inversely with those of proinflammatory chemokines, and IL‐22 can inhibit the release of proinflammatory mediators by human bronchial epithelial cells (39). Here, IL22 is linked to asthma.