title: Grand Challenges in Reproductive Endocrinology.
authors.affiliation: Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children and Reproduction, Copenhagen University Hospital, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark.
authors.forename: Claus Yding
authors.initials: CY
authors.lastname: Andersen
keywords: follicles; gonadotropins; ovary; peptide growth factors; reproductive endocrinology; seminiferous tubles; sex steroids; testes