1. Department of Histology, Microbiology and Medical Biotechnologies (A.F., B.A., E.S., C.C., R.S., A.G., C.F.), Centre for Male Gamete Cryopreservation, University of Padova, 35121 Padova, Italy
2. Department of Medical Pathophysiology (A.L.), University of Rome “La Sapienza,” 00100 Rome, Italy