RYR2 and heart disorder: Importantly, RyR2 hyperoxidation has been associated with reduced cardiac function and/or increased arrhythmic potential in various cardiac diseases including heart failure [49], infarct [5, 10], diabetic cardiomyopathy [7, 28, 37], age-related cardiac dysfunction [15, 18], and even inherited cardiac arrhythmia syndromes [23].