Focusing first on fibrosis pathways, we detected no differences between control and IPF fibroblasts with regard to the synthesis and release of collagen as well as gene expression and activity of MMP-1 (the dominant MMP, Fig. 4A) either when treated or untreated with TGF-β1, and PPAR-β and PPAR-γ agonists. This evidence concerns the gene PPARG and idiopathic pulmonary fibrosis.