MMP12 and pulmonary fibrosis: Therefore, PAI-1, in conjunction with other coagulation factors such as von Willebrand or matrix metalloproteinase 12, is considered a causative factor in some progressive fibrotic disorders, particularly in the context of pulmonary fibrosis, where transforming growth factor (TGF)-β appears to be increased due to excessive extracellular matrix deposition and reduced matrix breakdown, which are important in the pathophysiology of systemic sclerosis [9].