MMP-9 (Gelatinase B) is a metalloproteinase that degrades multiple extracellular matrix components including Gelatin, Collagens III, IV, V, and XI, Elastin, Nidogen-1, and Vitronectin. It also cleaves a variety of chemokines and growth factors (e.g. IL-1 beta, CXCL8/IL-8, CXCL7, CXCL4, CXCL1, Latent TGF-beta, membrane bound TNF-alpha, VEGF, and FGF basic), Amyloid beta peptide, Substance P, and Myelin Basic Protein. MMP-9 can trigger signaling through various transmembrane proteins or inhibit signaling by inducing their shedding from the cell surface (e.g. CD44, E-Cadherin, Integrins, ICAM-1, and CD25/IL-2 R alpha). The activity of MMP-9 is regulated by its association with the TIMP-1 protease inhibitor. Circulating levels of MMP-9 are elevated in many inflammatory disorders including intraluminal thrombus formation, atherosclerosis, Crohn’s disease, hepatitis C virus infection, colorectal cancer, and Duchenne muscular dystrophy.