MMP9 and cancer: Several lines of evidence have indicated that MMP species such as MMP-2, MMP-7, MMP-9 and MMP-14 (MT1-MMP) have key roles in invasion and metastases of cancer cells (Liotta and Kohn, 2001; Shiomi and Okada, 2003; Deryugina and Quigley, 2006).