MMP3 (matrix metallopeptidase 3) is a zinc-dependent metalloproteinase that degrades extracellular matrix components including collagens, fibronectin, and proteoglycans, playing crucial roles in tissue remodeling and pathological processes. The enzyme demonstrates broad substrate specificity and activates other matrix metalloproteinases and growth factors 1. MMP3 exhibits significant clinical relevance in multiple disease contexts. In cancer, MMP3 upregulation via epigenetic mechanisms involving KDM6A promotes brain metastasis in triple-negative breast cancer, with KMT2C-mutant tumors showing elevated MMP3 levels 1. The gene serves as a hub biomarker in head and neck squamous cell carcinomas, associated with poor survival and metastasis 2. Genetic polymorphisms in MMP3, particularly rs679620 and rs520540, influence disease susceptibility with complex associations: these variants show protective effects against ischemic stroke but increased hemorrhagic stroke risk in Chinese populations 3. In musculoskeletal medicine, MMP3 variants affect injury susceptibility, with the rs679620 G allele overrepresented in anterior cruciate ligament ruptures 4 and rs522616 polymorphism influencing muscle strength recovery after exercise in a sex-dependent manner 5. Additionally, MMP3 polymorphisms are associated with coronary artery disease risk and post-PCI outcomes 67.