Expansion of EBV-specific T cells in patient 2 after T-cell transfer. (A) EBV DNA levels in peripheral blood cells (copies per 20 000 cells) and in throat lavage fluid (copies per milliliter). (B) Absolute numbers of CD8⁺ and CD4⁺ T-cell subsets in peripheral blood. (C) Frequencies of CD8⁺ T cells specific for EBV epitopes in total PBLs were assessed by HLA-peptide multimer staining. Immediate-early and early lytic cycle antigens (epitopes YVL and GLC) and latent antigens (epitopes CLG and RRIY) were included in the analysis.