RYR2 and myocardial ischemia: Studies have shown that activation of CaMKII can be detected in the initial stage of cardiac ischemia/reperfusion [8, 9], and activation of CaMKII can result in RyR2 channel opening through phosphorylation of Ser2814 on RyR2, thereby increasing SR Ca2+ release, which regulates myocardial contraction [4].