CD95 ligand-induced caspase-8 and caspase-3 cleavage. PML-RARA-positive cells (NB4, lanes 1-3), and PML-RARA-negative cells (AML-2, AML-3, HL60, and Jurkat, lanes 4-15) were cultured for 24 hours in media supplemented with 0, 50, or 100 ng/mL FAS ligand. Caspase-8 activation (top panels) and capase-3 activation (middle panels) were assessed by monitoring the formation of cleaved product (p41/43 and p18 for caspase-8 and p19/17 for caspase-3) using immunblot analysis.