24). Other studies have shown that FNDC5 overexpression improved insulin resistance via AMPK pathway (Ref. 25). At the systemic level, irisin maintains glucose and lipids homoeostasis which is crucial in treatment for type 2 diabetes mellitus (T2DM), obesity or other metabolic diseases (Ref. 26). This evidence concerns the gene FNDC5 and obesity due to melanocortin 4 receptor deficiency.