1. Direction of Chronic Infections and Cancer, Research Center in Infection Diseases, National Institute of Public Health, Avenida Universidad 655, Cerrada Los Pinos y Caminera, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100 Morelos, MEX, Mexico
2. National Institute of Medical Sciences and Nutrition “Salvador Zubirán,” Vasco de Quiroga 15, Tlalpan, 14000 México, DF, Mexico