1. Istituto di Cancerologia, Università di Bologna Medical School, Bologna, Italy
2. Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
3. Stazione Zoologica A. Dohrn, Napoli, Italy
4. Istituto di Radioterapia, Università di Bologna Medical School, Bologna, Italy
5. Department of Radiation Oncology, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania, USA