MMP9 and aneurysm: In the mouse CaPO4-induced aneurysm model, aneurysmal tissues expressed significantly higher levels of CD11b (0.0416% ± 0.004354% vs. 2.492% + 0.5137%, p < 0.01), TRAP (0.3% ± 0.1679% vs. 2.008% ± 0.2024%, p < 0.001), cathepsin K (0.272% ± 0.03169% vs. 2.72% ± 0.3362%, p < 0.01), and MMP-9 (0.202% ± 0.03247% vs. 3.02% ± 0.33%, p < 0.001) compared to untreated contralateral carotid artery controls (Figure 4A).