IL-17 gene knockout mice with AE-IPF had quicker body weight recovery, milder pulmonary inflammation and fibrosis, stronger IL-22+CD4+T, TGF-β+ γδ T and Treg cell responses, and weaker neutrophil and eosinophil responses than wild-type mice with AE-IPF. Here, TGFB1 is linked to fibrosis.