During myocardial ischemia or reperfusion, many genes such as c-fos, c-jun, junB, Egr-1, HSP70 can be up-regulated [5–7], and some of these myocardial genes have been considered to be involved in the endogenous cardioprotection against myocardial ischemia-reperfusion injury. Here, JUN is linked to myocardial ischemia.