Previous studies have found that IL-13 signals through IL-13R2 to induce transforming growth factor beta (TGF-β) and fibrosis progression (Fichtner-Feigl et al., 2008), and silencing of IL-13Rα2 reduced TGF-β production and lung fibrosis (Fichtner-Feigl et al., 2006). This evidence concerns the gene TGFB1 and pulmonary fibrosis.