In all the patients with PCOS were described levels of seric AMH two to three times higher than normal, but there is no evidence that AMH excess is secondary to the large number of preantral and small antral follicles determined by chronic anovulation or if this excess represents the reason of growth-impairment of this follicles due to a higher intrinsic secretion of the granulosa cells that lead to chronic anovulation. The gene discussed is AMH; the disease is polycystic ovary syndrome.