AR and primary ovarian failure: Sen and Hammes recently elegantly elucidated AR effects in different organs/tissues by generating granulosa cell- and oocyte-specific ARKO mice, allowing determination of where androgen-dependent effects were located [21]: Almost all reproductive phenotypes observed in global ARKO mice proved explainable by AR expressions in granulosa cells, including premature ovarian failure (POF), subfertility with longer estrous cycles and fewer ovulated oocytes, more preantral and atretic follicles, fewer antral follicles and fewer corpora lutea.