Anti-third-party CTLs do not affect AML leukemic cells. Frozen AML cells (1 × 10⁶) obtained from patients in stage M1 to M2 or B-CLL cells from patients in stage IV were cultured alone (□) or together with 2 × 10⁵ allogeneic anti-third-party CTLs (▪). Following 72 hours of incubation, different wells were sampled and stained with the corresponding fluorescent Abs as described in “Materials and methods.” Subsequently, samples were analyzed by FACS for annexin staining. Values are expressed as annexin-positive cells from total CD33⁺ (for AML) or CD19⁺ (for B-CLL) cells (n = 3). Error bars indicate standard deviation (SD).