A recent meta-analysis including eight studies, with 918 PCOS patients and 529 controls, demonstrated that irisin levels were at least 45.78 ng/mL (95% confidence interval CI) (12.45, 79.12, p = 0.007) higher in PCOS patients, compared to healthy controls [50]. The gene discussed is FNDC5; the disease is polycystic ovary syndrome.