MMP13 and neoplasm: 5, 6 Matrix metalloproteinase-1 (MMP-1) may degrade a broad range of substrates including the interstitial types I, II, III collagens as well as casein and contribute to tumor growth and spread by altering the cellular microenvironment to favor tumor formation. 5, 6, 7, 8 Among secreted MMPs, MMP-2 and MMP-9 are known to play a major role in cancer invasion and metastasis development by their ability to degrade type IV collagen9. Furthermore, overexpression of MMP13 has been related to more aggressive tumors and poor prognosis in lung cancer10, 11.