PPARGC1A and idiopathic pulmonary fibrosis: Aside from ACTA2, the knockdown of HDAC7 by RNAi resulted in a significant reduction of TGF-β-upregulated profibrotic mediators NOX4 and CTGF in stimulated IPF fibroblasts, while expression of the TGF-β-suppressed antifibrotic gene PGC1A was increased.