EZH2 and idiopathic pulmonary fibrosis: 2009; Fujiwara et al. 2014; Hussain et al. 2009; Kikuchi et al. 2012; Simon and Lange 2008; Yang and Yu 2013). The purpose of this study was to examine the role of EZH2 in the development of IPF. We found that EZH2 was upregulated in the lungs of patients with IPF and in bleomycin‐challenged mice. The inhibition of EZH2 by the inhibitor DZNep or an EZH2 shRNA reduced fibroblast activation in vitro and in vivo. EZH2 mediates this effect by enhancing the TGF‐β signaling pathway, likely through pSmad2/3 nuclear translocation.