ACTA1 and idiopathic pulmonary fibrosis: A SIRT2 inhibitor or the knockdown of SIRT2 expression by small interfering RNA (siRNA) suppressed the expression of the fibro-genic genes α-SMA and fibronectin in TGF-β1-treated fibroblasts and primary lung fibroblasts derived from patients with idiopathic pulmonary fibrosis (IPF).