Z-VAD (OMe) -FMK (Z-Val-Ala-Asp (OMe) -FMK) is a cell-permeable and irreversible pan-caspase inhibitor[1]. Z-VAD (OMe) -FMK is an ubiquitin carboxy-terminal hydrolase L1 (UCHL1) inhibitor. Z-VAD (OMe) -FMK irreversibly modifies UCHL1 by targeting the active site of UCHL1[2].