MMP12 and aneurysm: In line with significant upregulation of MMP-12 in aneurysm, in animals injected with probe 3 the fluorescence signal in the aneurysmal left carotid artery was significantly higher than the signal in the control, contralateral artery in tissues harvested at 60 minutes (Fig. 6B and C, n = 3, p < 0.01).