COL3A1 and pulmonary fibrosis: To further investigate whether AC infection-induced lung inflammation leads to pulmonary fibrosis, we performed Masson staining, RT–qPCR and immunoblot analysis and found no obvious fibrosis in the mouse lung (S9A and S9B Fig), which was further confirmed by the lack of elevated transcript and protein levels of Col1a1, Col3a1, α-SMA and TGF-β (S9C–S9E Fig).