The formation of vascular atherosclerosis is associated with the production, stabilisation and detachment of an atherosclerotic plaque. The latter consists of a lipid core, a fibrous envelope and many inflammatory cells (including macrophages). The fibrous envelope, on the other hand, is made up of two proteins - collagen, elastin and a large group of proteolytic (i.e. protein-degrading) enzymes - metalloproteinases.