Michael von Wolff is Head of the Division of Gynaecological Endocrinology and Reproductive Medicine at the Women`s University Hospital, Berne, Switzerland. He has studied and worked in Germany, London, New York and most recently in Switzerland. His research focuses on fertility preservation and natural cycle IVF, as well as ovarian stimulation and ovarian tissue transplantation and has published several books and papers. He established the German-language network of fertility preservation before cytotoxic therapies “FertiPROTEKT” (www.fertiprotekt.com) in 2006. He also founded the ESHRE Task Force on Fertility Preservation, has co-founded the Special Interest Group “Fertility preservation” of European Society of Human Reproduction and Embryology, ESHRE and is Vice president of the International Society for Fertility Preservation, ISFP.   Frank Nawroth Prof. Dr. med., was a Senior Physician and Head of the Department of Gynecological Endocrinology and Reproductive Medicine at the University Women's Hospital in Cologne from 1999-2004, and since 2008 has been an Adjunct Professor of Gynecology and Obstetrics there. Since 2010 he has been working at the Center for Infertility, Prenatal Medicine, Endocrinology and Osteology at Barkhof, Hamburg, where he focuses mainly on fertility preservation and treatment of infertility. He has published several books and papers and is a member of the FertiPROTEKT board.