Although mRNA abundance of GDF9, but not BMP15, in human oocytes has been reported to be decreased in PCOS44, whether antral follicle arrest in PCOS is due to androgen-induced, RNF6-mediated AR ubiquitination and AR down-regulation and subsequent dysregulated GDF9 expression is not known. Here, GDF9 is linked to polycystic ovary syndrome.