Metformin can reduce the production and intestinal absorption of glucose, and overcome insulin resistance by increasing the uptake and utilization of peripheral glucose and improving insulin sensitivity.15 Current studies also show that metformin is moderately efficient in reducing body weight of overweigh and obese patients.16 Body weight reduction was reported to restore physical health and reproductive function of PCOS patients.15,17 For instance, Zhang et al.18 showed that weight loss of 6% -7% can restore normal ovulation in some PCOS patients. The gene discussed is INS; the disease is polycystic ovary syndrome.