Although IL-22 levels in the bronchoalveolar lavage fluid of IPF patients were comparable to those of healthy controls (131), Liang et al., 2013 (132) demonstrated that IL-22 mitigates epithelial-to-mesenchymal transition (EMT) in a bleomycin-induced model of pulmonary fibrosis. Here, IL22 is linked to idiopathic pulmonary fibrosis.