Given the remarkable similarities in biological properties between GDF-8 and GDF-11, the present study was designed to explore the effect and related underlying molecular mechanisms of GDF-11 on StAR expression in hGL cells and to examine whether the expression levels of GDF-11 in follicular fluid and hGL cells are varied between non-PCOS and PCOS patients. The gene discussed is GDF11; the disease is polycystic ovary syndrome.