FAS and central nervous system cancer: The CD95 knockout was functionally confirmed by demonstrating abrogation of DEVD-amc peptide-cleaving activity, which characterizes the activity of the apoptotic effector caspase 3 that mediates canonical CD95 signaling, in all selected CD95 knockout clonal sublines upon stimulation with exogenous CD95L alone and in combination with cycloheximide, which sensitizes glioma cells to apoptosis induction [22] (Fig. 3B).