ANXA5 and glioblastoma: As caspases appeared to have a central role in BKM120 and TRAIL-mediated apoptosis, LNZ308, U87 and primary patient GBM cells were preincubated with caspase-specific inhibitors (z-DEVD-fmk, caspase-3 inhibitor; z-IETD-fmk, caspase-8 inhibitor; z-VAD-fmk, pan-caspase inhibitor) and the effect on cell death was examined with Annexin V/PI assay.