1. From the Dompé Research Center, 67100 L'Aquila, Italy; the Laboratory of Molecular Immunoregulation, National Cancer Institute-Frederick Cancer Research Development Center, Frederick, MD 21702; Consorzio Biolaq, 67100 L'Aquila, Italy; the Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305; the Department of Biological Responses, Institute for Virus Research, Kyoto