The IL-1- and IL-17-associated signaling may propagate the TGF-β1-dependent pathway, forming an IL-1–IL-17–TGF-β1 axis to boost the development of pulmonary fibrosis in sustained type 1 inflammatory responses, whereas, IL-13 acts as the major driver of fibrosis in sustained type 2 inflammation via both TGF-β1-dependent and TGF-β1-independent pathways. This evidence concerns the gene IL13 and pulmonary fibrosis.