To investigate the potential role of irisin and leptin as markers of diabetes, Sahin-Efe et al. [42] measured the serum levels of irisin in stored blood samples of non-obese, obese, non-obese that, years after, had been diagnosed with diabetes type II, and observed that both leptin and irisin were significantly higher in obese subjects. The gene discussed is FNDC5; the disease is diabetes mellitus.