ACTA1 and idiopathic pulmonary fibrosis: Interestingly, despite effective downregulation of COL1A1, COL3A1 and FN, the expression of ACTA2 (α-SMA) was not observed to be reduced in response to pirfenidone as compared to vehicle, but was significantly suppressed in LBH589-treated IPF-fibroblasts (Fig 3D).