1. Faculty of Health Sciences, University Hospital of North Norway; Department of Dermatology; Harstad Troms Norway
2. Dessau Medical Center; Division of Evidence Based Dermatology; Dessau Germany
3. Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS); Dermatology and Skin Cancer Unit, Arcispedale Santa Maria Nuova; Reggio Emilia Italy
4. Aristotle University of Thessaloniki; 1st Department of Otolaryngology, Head & Neck Surgery; 3 Papazoli St. Thessaloniki Greece 54630
5. University of Padova; Dept. Surgery Oncology and Gastroenterology; Via Giustiniani 2 Padova Veneto Italy 35128
6. IOV-IRCCS; Istituto Oncologico Veneto; Padova Italy 35100
7. University of Toronto; Women's College Research Institute; 790 Bay St, Rm 735 Toronto ON Canada
8. University of Padova; Meta-Analysis Unit, Department of Surgery, Oncology and Gastroenterology; via Giustiniani 2 Padova Italy 35128
9. Hospital of Skin and Venereal Diseases; State Clinic of Dermatology; 17, Omirou street Thessaloniki Greece 55535