1. Department of Medical Biochemistry, Göteborg University, S-405 30 Göteborg
2. Genetique du Developpement des Melanocytes Institut Curie, Section Recherche UMR146 CNRS, Centre Universitaire, 91405 Orsay, France
3. Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
4. Department of Pathology, Umeå University, S-901 87 Umeå, Sweden
5. Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
6. Max-Planck Institut für Immunbiologie, D-79108 Freiburg, Germany