Matrix metallopeptidase 9 (MMP-9) is secreted from neutrophils, macrophages and a number of transformed cells. It is the most complex MMP family member in terms of domain structure and regulation of its activity. MMP family is involved in the breakdown of extracellular matrix in normal physiological processes as well as in disease processes. Most MMPs are secreted as inactive pro-proteins which are activated by the cleavage of extracellular proteinases. MMP-9 degrades various substrates including gelatin, collagen types IV and V, and elastin. It is involved in inflammatory responses, tissue remodeling, wound healing, tumor growth and diseases including systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. MMP-9 is rega