FNDC5 and myocardial infarction: A previous study have shown that irisin levels were lower in myocardial infarction (MI) and coronary atherosclerosis diseases (CAD) implying that their production may depend on myocardial blood supply [39], while another study suggested that serum irisin level was an independent predictor of coronary artery severity in patients with stable coronary artery disease [40].