MMP9 and idiopathic pulmonary fibrosis: The present study provides evidence for the anti-inflammatory role of erythropoietin through COX-2 expression, its antioxidant role through i-NOS expression, its protective role through EPO-R expression, and its antiapoptotic role through MMP-9 and Cyt-C expression in an experimental bleomycin-induced rat model of IPF.