MMP-9, or Matrix Metalloproteinase-9, is an enzyme that plays a crucial role in the breakdown of extracellular matrix components. It is involved in various physiological processes, including tissue remodeling, wound healing, and inflammation. MMP-9 is produced by several cell types, including macrophages and fibroblasts, and is activated in response to various stimuli. In addition to its normal functions, MMP-9 is also implicated in several pathological conditions, such as cancer, arthritis, and cardiovascular diseases. Elevated levels of MMP-9 can contribute to disease progression by promoting tissue degradation and inflammation, making it a potential target for therapeutic interventions.