Since epigenetic inhibitors have been shown to restore COX-2 expression and PGE2 production in lung fibroblasts from IPF patients by reversing the repressive histone modifications [3,5], the aim of this study was to evaluate the effect of these drugs on COX-2 downregulation associated with TGF-β1-induced activation of normal human lung fibroblasts. This evidence concerns the gene PTGS2 and idiopathic pulmonary fibrosis.