In vivo expansion and clinical benefits of EBV-specific T cells. (A) Frequencies of peripheral blood T cells responding to EBV-LCL by IFN-γ secretion before and after CTL infusion in 12 patients. Individual haploidentical recipients (n = 5) are represented by circles, and MUD recipients are represented by triangles (n = 7). Mean values are represented by lines: solid for haploidentical transplant recipients and dashed for MUDs. (B) Increase in the mean frequency of EBV-LCL-responsive peripheral blood T cells in patients 1, 2, and 3 is related to a decrease in EBV-DNA levels.