1. From the Servicio de Inmunologı́a, Hospital de la Princesa, Universidad Autónoma de Madrid, Madrid, Spain; the Department of Pathology, Stanford University, Stanford, CA; the School of Medicine, University of San Luis Potosı́, San Luis Potosı́, Mexico; the Servicio de Inmunologı́a, Hospital General Universitario Gregorio Marañón, Madrid, Spain; the Servei d'Immunologia, Hospital Clinic, Barcelona, Spain; and the Tumor Immunology Program, German Cancer Research Center, Heidelberg, Germany.