More importantly, recent studies found that the expression of SIRT1 in the ovaries of PCOS rats was significantly decreased, which could be improved by metformin treatment [41, 42], and consistently, our data showed that SIRT1 was down-regulated in the ovary of POCS rats, which was restored the Diane-35 plus metformin treatment. The gene discussed is SIRT1; the disease is polycystic ovary syndrome.