1. Department of Public Health and Microbiology, Medical School, University of Turin, Turin, Italy.
2. Department of Clinical and Experimental Medicine, Medical School, University of Eastern Piedmont “A. Avogadro,” Novara, Italy.
3. Infection and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France.
4. Department of Internal Medicine, Center for Experimental Research and Medical Studies, San Giovanni Battista Hospital, Turin, Italy.