FNDC5 and coronary artery disorder: Irisin is a myokine associated with increased energy expenditure due to its ability to stimulate browning of white adipose tissue, which is secreted after exercise.[39] Irisin levels are reported to be low in obese individuals, patients with T2DM, and coronary artery disease.[40–42] Liu et al[41] showed that irisin levels were lower in long-standing T2DM patients than in non-diabetic controls.