Difference between effector CD8⁺ T-cell subsets in terms of susceptibility to dying. (A) Purified CXCR1⁺ and CXCR1⁻ effector subsets were stimulated or not with solid-phase anti-CD3 mAb and cultured with or without IL-2 (200 U/mL) for 48 hours. Doublet cells were excluded from the CD3⁺CD8⁺ population and then the percentage of annexin V⁺ cells was analyzed. (B) The mean percentage of annexin V⁺ cells in each effector subset from 7 individuals is shown with the SD. *Significant statistical difference at the indicated level.