[1] Beaumont Hosp, Dept Dermatol, Dublin 9, Ireland
[2] Univ Calif San Francisco, Dept Dermatol, San Francisco, CA 94143 USA
[3] German Canc Res Ctr, Div Viral Skin Carcinogenesis, D-6900 Heidelberg, Germany
[4] German Canc Res Ctr, Div Viral Transformat Mech, D-6900 Heidelberg, Germany
[5] Leiden Univ, Med Ctr, Dept Dermatol, Leiden, Netherlands
[6] Baskent Univ, Fac Med, Dept Dermatol, TR-06490 Ankara, Turkey
[7] Aristotle Univ Thessaloniki, Sch Med, Papageorgiou Hosp, Dept Dermatol, GR-54006 Thessaloniki, Greece