Matrix metalloproteinases (MMPs) are a family of at least 23 structurally related, zinc-containing enzymes that have the ability to breakdown connective tissue. MMP-2, along with MMP-9, belongs to the gelatinase group of MMP’s which have three repeats of a type II fibronectin domain inserted in the catalytic domain. MMP-2 has shown substrate specificity to collagens types I, II, and III as well as the extracellular matrix component aggrecan.