Since previous studies have demonstrated association of histone modifications (e.g. histone deacetylation and H3K27me3) and DNA methylation with COX-2 repression in IPF and human gastric carcinoma [3,5,24], we went on to investigate the potential role of epigenetic modifications in TGF-β1-induced COX-2 downregulation in F-NL and whether these modifications could be altered by SAHA. This evidence concerns the gene PTGS2 and idiopathic pulmonary fibrosis.