Professor Gerd Gross has been Director of the Department of Dermatology and Venereology at the University of Rostock, Germany, since 1996. He is a recognized authority in the epidemiology, diagnosis, treatment, and prevention of sexually transmitted diseases. His particular field of interest is the impact and control of viruses in clinical medicine. He has been President of the German STD Society since 1998 and also Vice-President of the Paul Ehrlich Society for Chemotherapy. Professor Gross has published a large number of journal articles and five books in the field, including “Human Papillomavirus Infections. A Clinical Atlas”. Dr. Stephen Tyring is a Clinical Professor in the Departments of Dermatology, Microbiology/Molecular Genetics, and Internal Medicine at the University of Texas Health Science Center at Houston. Dr. Tyring sits on several editorial boards and serves as a reviewer for a number of prestigious journals. He has been principal investigator for more than 200 successfully completed clinical trials. Dr. Tyring’s research interests include the therapy and prevention of various mucocutaneous diseases, especially those disorders with an infectious and/or immunological basis. He is the author of more than 600 journal articles and book chapters as well as eight books, including one on sexually transmitted infections.