MMP9 and myocardial infarction: It is now well-established that MMP-9 expression was associated with the progression of atherosclerosis, and that MMP-9 genetic polymorphism was significantly correlated with acute myocardial infarction but not degree of coronary artery stenosis.9 Shevchenko et al. reported that the lesion area of G allele carriers significantly exceeded that of C allele ones, and that the stenotic rate of coronary artery was significantly correlated with GG genotype.