1. Skin Cancer Unit, German Cancer Research Center (DKFZ); Heidelberg Germany
2. Department of Dermatology; Venereology and Allergology, University Medical Center Mannheim, Ruprecht-Karl University of Heidelberg; Mannheim Germany
3. Department of Dermatology; University Hospital Tuebingen; Tuebingen Germany
4. NCT Tissue Bank, National Center of Tumor Diseases (NCT); Heidelberg Germany
5. Institute of Pathology, University Hospital Heidelberg; Heidelberg Germany
6. Department of Dermatology; University Hospital Heidelberg; Heidelberg Germany
7. Institute of Surgical Pathology, University Hospital Zurich; Zurich Switzerland
8. Division of Biostatistics; German Cancer Research Center (DKFZ); Heidelberg Germany