GX15-070 activates the intrinsic apoptotic pathway in a caspase-independent manner. UPN-1 cells were treated with 0.5 μM GX15-070 for 16 hours in the presence or absence of z-VAD-fmk (50 μM). Bax/Bak conformational changes, caspase-3 activation, loss of ΔΨ_m, and PS exposure were analyzed as described in “Patients, materials, and methods.” The percentages inside each chart refer to the population in black. These experiments have been performed twice with similar results and therefore 1 representative experiment is shown.