Association between BH3 profiling and BH3 mimetic activity. (A) Induction of apoptosis shown as a percentage of viable (annexin V negative/Hoechst positive vs control) cells after 24-hour exposure to an increasing concentration of DMSO alone or a BH3 mimetic (1 nM, 10 nM, 100 nM, and 1 μM): venetoclax, AZD5991, or S63845 (n = 13; mean ± standard error of the mean [SEM]). (B-D) Association between cyt c release induced by venetoclax at 0.1 μM (B) and MS1 peptide at 5 μM (C-D) with induction of apoptosis shown as a percentage of viable (annexin V negative/Hoechst positive) cells vs DMSO, after 24-hour exposure to venetoclax 10 nM (B), AZD5991 100 nM (C), or S63845 100 nM (D). Results show individual values for 13 different T-PLL samples and simple linear regression. (E) Induction of apoptosis shown as the percentage of viable (annexin V negative/Hoechst positive vs control) cells after 24-hour exposure to DMSO, AZD5991 100 nM, S63845 100 nM, or A-1331852 1 μM and 4-hour exposure to DMSO alone or an increasing concentration of venetoclax (1 nM, 10 nM, 100 nM, 1 μM, and 10 μM; n = 5; means ± SEM). (F) Same data set as in panel E, focused on venetoclax at 100 nM and showing individual values (n = 5; paired Student t test). *P < .05; P < .01; ***P < .001.