MMP9 and rheumatoid arthritis: Increased expression and activity of MMPs has been linked with rheumatoid arthritis, tissue degradation, bone resorption [4,5], tumor metastasis and ischemic injury [6]; MMP-9 for instance is physiologically found in the heart and its up regulation is associated with heart failure, indicating a possible role of MMP-9 in cardiomyopathy [7].