CNA12 EBV-CTLs lack alloreactivity versus HLA-mismatched donors. Alloreactive potential of unmanipulated PBMCs as well as CNA12-transduced EBV-CTLs from the same donor using a primary mixed lymphocyte reaction. Unmanipulated PBMCs proliferated significantly (P < .001) in response to allogeneic, irradiated PBMCs compared with the proliferation of CNA12-EBV-CTLs unselected or GFP⁺ selected. Data show the mean values and SEM of experiments from 4 donors.