MMP9 and atherosclerosis: Second, atherosclerotic lesions of cholesterol‐fed rabbits are rich in macrophage‐derived foam cells, which facilitates the analysis of macrophage functions in the arterial wall.32 To the best of our knowledge, this is the first report to demonstrate that overexpression of MMP‐9 in macrophages is not only involved in the progression of atherosclerosis but also increases vascular calcification.