Affiliation: | (1) Department of Obstetrics and Gynecology Division of Reproductive Endocrinology, New England Medical Center, 02111 Boston, Massachusetts;(2) Department of Anatomy and Cellular Biology, Tufts University School of Medicine, 02111 Boston, Massachusetts;(3) Division of Reproductive Biology Department of Obstetrics and Gynecology School of Medicine, University of Pennsylvania, 19104 Philadelphia, Pennsylvania;(4) Department of Biology, University of Pennsylvania, 19104 Philadelphia, Pennsylvania |