LFA-1–mediated adhesion of patient no. 11 and control PBL measured with the fluorescent beads adhesion assay. Double staining with CD10-FITC MoAb was used to distinguish between the leukemic (CD10⁺) cell population and the CD10⁻ cell population within one sample. (A) Adhesion of the different CD10 cell populations after stimulation with PMA. (B) LFA-1–mediated adhesion of the leukemic (CD10^dim and CD10^bright) and the CD10⁻ cell population, in comparison with the adhesion of PBL from a healthy donor. Standard deviations are less than 5%. (C) LFA-1 expression of the various CD10 cell populations.