SPARC and idiopathic pulmonary fibrosis: In the three IPF fibroblast primary cell lines, we found that PP242 (2.5 μM) and MLN0128 (0.2 μM), but not rapamycin (0.05 μM), suppressed by 50%–80% the basal and TGF-β-inducible expression of type I collagen, the alternatively spliced extra type III domain A fibronectin variant (EDA-FN), α-SMA, and SPARC (Fig. 1B).