1. Department of Dermatology; Hôpital Erasme; Université Libre de Bruxelles; Brussels Belgium
2. Molecular and Pharmaco-Epidemiology Unit; Department of Experimental Oncology; European Institute of Oncology; IRCCS, Milan Italy
3. Cancer Epidemiology Unit; University Institute of Social and Preventive Medicine; Lausanne Switzerland
4. Dermatology Department; Elias University Hospital; Carol Davila University of Medicine and Pharmacy; Bucharest Romania
5. Department of Dermatology; Hospital Central de la Defensa Gómez Ulla; Madrid Spain