We would like to emphasize that in contrast to most of the previous publications we performed a post-treatment (to mimic the clinical situation) with a combination of PPAR-β/δ and PPAR-γ agonists to reverse the TGF-β1-induced fibrotic phenotype of IPF fibroblasts. The gene discussed is TGFB1; the disease is idiopathic pulmonary fibrosis.