Effect of prognostic markers on B-PAC-1–induced apoptosis in CLL lymphocytes. B-PAC-1–induced apoptosis was compared in CLL samples obtained from patients with different cytogenetics (A), with 17p chromosome deletion (B), different Rai stages (C), with or without IgVH mutation (D), ZAP70 status (E), with or without prior fludarabine exposure (F), peripheral white blood cell count (G), and level of β2-microglobulin (H). Apoptosis was measured by Annexin V/PI staining assay and unstained cells were considered viable cells; time-matched DMSO-treated cells served as control. 11q, chromosome 11q deletion; 17p, chromosome 17p deletion; β2-M, β2-microglobulin; D13, chromosome 13q deletion; ND, not determined; NEG, negative for any cytogenetic factor; T12, trisomy 12; WBC, white blood cell.