Other studies have shown that the involvement of MMPs in atherosclerosis leads to a reduction in atherosclerotic lesions when using double knockout animals for ApoE-⁄- and MMP-2-⁄- [23], MMP-8-⁄- [20], and MMP-9-⁄- and MMP-12-⁄- [25]. Here, MMP9 is linked to atherosclerosis.