De la Iglesia et al. [13] reported that in MetS subjects, the depletion of irisin after a weight loss program significantly correlated with changes in total cholesterol, total cholesterol/high-density lipoprotein (HDL) cholesterol ratio, low-density lipoprotein (LDL) cholesterol and apolipoprotein B, independently of changes in body weight. The gene discussed is FNDC5; the disease is metabolic syndrome.