MMP13 and diabetes mellitus: In contrast, MMP-13 (collagenase-3), which in rats appears to be constitutive and analogous to MMP-1 (collagenase-1) in humans [19, 33], did not appear to be affected either by diabetes or by CMC2.24 during the 7-day treatment of the wounds (data not shown) indicating that this novel treatment selectively inhibits pathologically excessive MMPs but does not suppress constitutive MMPS needed for normal/physiologic connective tissue turnover.