ACTA1 and idiopathic pulmonary fibrosis: Sequentially diluted INS018_055 led to complete and concentration-dependent inhibition of TGF-β-mediated α-SMA expression in the fibroblasts of three donors with IPF, with IC50 values of 50 nM, 79 nM and 63 nM (Fig. 2d and Supplementary Information 6).