1. Dipartimento Farmaco Chimico Tecnologico, University of Siena, via A. Moro 2, I-53100 Siena, Italy
2. Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, BioLife Science Building, Suite 333, 1900 N. 12th Street, Philadelphia, Pennsylvania 19122, United States