MMP9 and asthma: Corroborating our findings (6), in an experimental model of asthma induced by lipopolysaccharide (LPS), there was an increase in the number of cells positive for MMP-9, MMP-12, TIMP-1, and TGF-β, as well as an increase in the volume fraction of collagen fibers I and III, decorin, actin, biglycan, lumican, and fibronectin in the alveolar septum.