MMP19 and idiopathic pulmonary fibrosis: MMP28 is the latest member of the MMPs family and structurally belongs to the MMP19 subfamily,[13] which we revealed as over-expressed in IPF lung epithelium.[8] MMP28 has been reported upregulated in some pathologic conditions such as osteoarthritis,[14] gastric cancer[15] and certain heart conditions such as acute myocardial infarction and unstable angina.[16,17] Recently, we have shown that MMP28 is upregulated in IPF and that MMP28 deficient mice are protected from bleomycin-induced lung fibrosis suggesting a profibrotic role.[18]