1. Department of Life, Health and Environmental Sciences, University of L’Aquila, L’Aquila, Italy
2. Center for Reproductive Sciences, Department of Obstetrics and Gynecology, University of California San Francisco, San Francisco, CA, USA
3. Family Planning Research Institute and Center for Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
4. Deparment of Anatomy, Histology, Forensic Medicine and Orthopaedics, La Sapienza University of Rome, Rome, Italy