CD8A and neoplasm: We used these expanded CD8+ CMV reactive T cell lines as well as a long-term CMV pp65aa495–503 specific T cell clone (clone p21) for in vitro cytotoxicity assays at different E:T ratios (with K562-A2 tumor cells as targets) and different pp65aa495–503 peptide concentrations either in the presence or absence of arginine.