PTGS2 and idiopathic pulmonary fibrosis: Cyclooxygenase 2 (COX2) expression—a biosynthetic enzyme for antifibrotic prostaglandin production—is suppressed in IPF due to decreased histone acetylation (Coward et al., 2009), and histone deacetylase 4 (HDAC4) activity mediates TGFβ stimulated myofibroblast differentiation in a response that can be inhibited by global inhibition of HDACs (Glenisson et al., 2007).