Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that degrade substances within the extracellular matrix. The MMP family includes six different groups of enzymes: collagenases, gelatinases, stromelysins, transmembrane MMPs, matrilysins and others. MMPs are secreted as proenzymes that have to be cleaved in order to be activated. Other MMPs, plasmins as well as other factors activate MMPs. MMPs are thought to play an important role in tissue remodeling associated with various physiological and pathological processes. MMP9 degrades of proteins in the extracellular matrix and activates growth factors like proTGFb and proTNFa. MMP-9 contributes to the invasion and metastasis of various human malignancies. Clone F11P2C3 has been shown to be useful for western blotting and immunohistochemistry of human MMP9.