Mmp3 encodes a member of the matrix metalloproteinase family of extracellular matrix-degrading enzymes that are involved in tissue remodeling, wound repair, progression of atherosclerosis and tumor invasion. The encoded protein is activated by the removal of an N-temrinal activation peptide to generate a zinc-dependent endopeptidase with a broad range of substrates such as proteoglycans, laminin, fibronectin, elastin, and collagens. Mmp3 is located in a cluster of other matrix metalloproteinase genes on chromosome 9.