Subsequently, a similar role for Mecp2 has been described in the bleomycin model of lung fibrosis and in the development of interstitial fibrosis in a mouse model of myocardial infarction, and other reports have confirmed profibrogenic functions for Mecp2 in myofibroblasts from multiple tissue origins.7, 8, 9 In our earlier studies, we focused on Mecp2 as a key transcriptional repressor of the nuclear hormone receptor PPAR-γ because down-regulation of PPAR-γ is a necessary event for HSCs to adopt a fully transdifferentiated myofibroblast state.6 This evidence concerns the gene MECP2 and pulmonary fibrosis.