Samples collected from adult AML patients at relapse do not consistently show further apoptosis reduction or increased BCL-2 positivity as compared with samples collected from the same patients at diagnosis. (A) Median values and ranges of apoptosis frequencies for untreated cells in diagnosis (presentation) and relapse samples collected from 14 adult AML patients. (B) Median values and ranges of BCL-2–positive fractions for untreated cells in presentation and relapse samples collected from 14 adult AML patients. As in Figs 3 and 5, control bone marrow myeloid data are represented in shaded bars. (C) Comparison of apoptosis and BCL-2 positivity data for each of these samples.