H-MMP-7 is a member of the Matrix metalloproteinase family of endopeptidases, containing the canonical HExxHxxGxxH motif as a zinc binding active site. MMP-7 and MMP-26 (Matrilysin-2) are the only MMPs discovered that completely lack a hemopexin “regulatory domain” or hinge region. Like the other MMPs, MMP-7 is secreted as a zymogen, then activated. The 28kD form is reduced to 18kD by enzymatic cleavage after the conserved “cysteine switch.” MMP-7 is not constitutively produced. It is produced on demand in specific tissues. MMP-7 substrate specificity is broad, most closely resembling the activity of MMP-3 (Stromelysin-1). When MMP-7 production is stimulated, native MMP inhibitors (TIMPs) usually follow to quench them.