A recent study of our own research group on myocardial infarctions came up with positive immunohistochemical staining for matrix metalloproteases (MMP) 2 and 9 and their inhibitor TIMP-1 (tissue inhibitor of matrix metalloproteases) not only in ischemic areas, but also adjacent to wounds inflicted mechanically by electrodes or vessel ligations in rats’ hearts [6]. This evidence concerns the gene TIMP1 and myocardial infarction.