MMP7 was initially characterized by Woessner et al. It digests components of the extracellular matrix, cleaves the α 2 (I) chain of gelatin more rapidly, and digests the B chain of insulin at Ala14-Leu and Tyr16-Leu, and has no action on collagen types I, II, IV, V. The optimal pH of MMP7 is at 7 and the pI is at 5.9. MMP4 is inhibited by α 2-macroglobulin and TIMP. The inhibition of MMP7 activity commonly relies on metal-chelating agents including EDTA and 1,10-phenantroline, especially zinc chelation. Therefore, the selectivity of MMP7 inhibition is challenging since almost all members of MMPs family contain catalytic domains with zinc binding sites. TIMP-1 and 2 noncovalently bound to active MMP7 at the catalytic site inhibiting MMP7 activity. The activated MMP7 can also cleave the propeptides of proMMP2 and proMMP9 to facilitate tumor invasion.