1. Doping Control Laboratory, Department of Clinical Chemistry, Microbiology and Immunology; Ghent University; Technologiepark 30; 9052; Zwijnaarde; Belgium
2. Department of Endocrinology-Andrology, Center for Sexology and Gender Problems; University Hospital, Ghent University; De Pintelaan 185; 9000; Gent; Belgium
3. Department of Hematology; University Hospital, Ghent University; De Pintelaan 186; 9000; Gent