Moreover, the mRNA expression levels of ERα and ERβ in cumulus cells from patients with PCOS are significantly lower than those from healthy controls (75), and considerable alterations in the expression levels of ERα and ERβ are also found in theca and granulosa cells (77); taken together, these findings suggest abnormal folliculogenesis in patients with PCOS. The gene discussed is ESR2; the disease is polycystic ovary syndrome.