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). Here, IL13 is linked to pulmonary fibrosis.