1. Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland.
2. Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland.
3. Department of Dermatology, Skin Cancer Center, University Hospital Zurich, Zurich, Switzerland.
4. UCSF Helen Diller Family Comprehensive Cancer Center, Cardiovascular Research Institute and Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA.