MMP9 and atherosclerosis: The expression of three markers of ECM turnover was compared to Fap expression in atherosclerotic plaques: Ki-67, a marker of active cell division in different stages of atherosclerosis; procollagen type III (Col3a1), a marker of collagen synthesis and degradation in ECM; and metalloproteinases 9 (Mmp-9), which is induced by inflammation in atherosclerosis with higher levels of Mmp-9 in plaques favoring ECM destruction (Figure 5).