IL17A and idiopathic pulmonary fibrosis: TH17 cells can release a large amount of IL‐17A to promote G‐CSF and KC secretion, and G‐CSF can mobilize neutrophils from the bone marrow to peripheral blood.26 KC can induce the chemotaxis of pro‐inflammatory cells in particular neutrophils to the lung,27 consequently increasing inflammatory monocytes and neutrophils and lymphocytes in the BALF of the mice with AE‐IPF and exacerbating the local inflammatory responses in the lung.