TGFB1 and pulmonary fibrosis: The suppression of IL-13Rα2 expression, the receptor of IL-13 involved in TGF-β signaling, by loading small interfering RNA (siRNA) to IL-13Rα2 in HVJ-envelope vectors led to the neutralization of bleomycin-induced pulmonary fibrosis and retardation of collagen deposition [437].