1. Laboratory of Immunoregulation
2. Dipartimento di Medicina Sperimentale, University of Genova, Genova 16132, Italy
3. Istituto San Raffaele, Istituto di Ricovero e Cura a Carattere Scientifico, Rome 00163, Italy
4. Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
5. Department of Medicine, University of Toronto, Toronto M5S 1A1, Ontario, Canada
6. Istituto Nazionale per la Ricerca sul Cancro, 16132 Genova, Italy