1. Department of Endocrinology, University Hospital Ghent, Belgium
2. Study Centre for Carcinogenesis and Primary Prevention of Cancer, Department of Radiotherapy, Nuclear Medicine and Experimental Cancerology, University Hospital Ghent, Belgium
3. Flemish Institute of Technological Research (VITO), Centre of Expertise in Environmental Toxicology, Mol, Belgium
4. Provincial Institute for Hygiene, Antwerp, Belgium
5. Department of Human Heredity, Catholic University of Leuven, Leuven, Belgium