Z-VAD-FMK (Z-Val-Ala-Asp(OMe)-FMK) is a cell-permeable, irreversible pan-caspase inhibitor. Z-VAD-FMK inhibits caspase processing and apoptosis induction in tumour cells in vitro with an IC50 of 0.0015 - 5.8 mM). Z-VAD-FMK is O-methylated in the P1 posit