Expression of CD10 by apoptosing CD8-positive T-cell blasts. T-cell blasts from IL-2–dependent continuous T-cell lines were cultured in the presence or absence of IL-2 (20 U/mL) for 48 hours. The cells were obtained, double stained as indicated, and analyzed by flow cytometry. The quadrants were drawn based on the analysis of negative controls stained with an irrelevant (isotype-matched) MoAb or analyzed in the absence of Annexin-V-FITC staining.