Recent data indicate that irisin may be involved in cardiovascular physiology, with evidence emerging that it plays a role in atherosclerosis [20–22] and can predict cardiovascular disease (CVD) risk [23, 24] This highlights the potential significance of irisin as a biomarker in T2DM patients who are at an increased CVD risk [25]. Here, FNDC5 is linked to type 2 diabetes mellitus.