A case-control study including 40 women with PCOS and 40 age- and BMI-matched controls found that serum Nrg4 levels were significantly higher in patients with PCOS than in controls and positively correlated with HOMA-IR, hs-CRP, and circulating insulin (Temur et al., 2017). The gene discussed is INS; the disease is polycystic ovary syndrome.