1. Department of Dermatology, University of Pennsylvania, Philadelphia, PA 19104, USA.
2. Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
3. Laboratory of Molecular and Cellular Biology, Istituto Dermopatico dell’Immacolata (IDI-IRCCS), 00167 Rome, Italy.
4. Institute for Research in Biomedicine, 6500 Bellinzona, Switzerland.