One possibility accounting for this discrepancy may be that mitochondrial damage caused by ETC mainly occurs in ischemia period, the continuation of enhanced mitochondrial aerobic respiration without oxygen results in deletion of cardiolipin, leading to loss of cytochrome c and the onset of mitochondrial permeability transition, which taken together promote myocardial cell apoptosis32, 33. This evidence concerns the gene CYCS and ischemia.