Fap distribution was characterized in mouse atherosclerotic plaques relative to other markers of activated smooth muscle cells, such as alpha smooth muscle actin and myosin heavy chain (Acta2 and Myh2), ECM turnover (Ki-67, procollagen III and Mmp-9), and inflammation in atherosclerosis (Cd-44, Il-12 and Tgf beta) using immunohistochemistry (IH) and RT-PCR analysis. This evidence concerns the gene MMP9 and atherosclerosis.