1 Skin Cancer Center, Department of Dermatology, Ruhr-University Bochum, Bochum, Germany.
2 Translational Skin Cancer Research, DKTK Partner Site Essen/Düsseldorf, West German Cancer Center, Dermatology, University Duisburg-Essen, Essen, Germany.
3 German Cancer Research Center (DKFZ), Heidelberg, Germany.