γ-Herpesviruses. An important role for the cytotoxic T cell response during EBV infection is supported by the large expansion of EBV-reactive CD8 + T cells that defines IM, their sometimes diminished response in HL and NPC patients (Fogg et al. 2009; Gandhi et al. 2006; Li et al. 2007), and strong HLA class I associations localizing to the residues of the peptide-binding groove. This evidence concerns the gene CD8A and nasopharyngeal carcinoma.