Z-FA-FMK is widely used in biochemical research as a potent and irreversible inhibitor of cysteine proteases. It is particularly valuable in studying apoptosis, as it inhibits caspases, which are crucial enzymes in programmed cell death. This compound helps researchers understand the mechanisms of cell death and survival pathways, making it a critical tool in cancer research and the development of therapeutics targeting apoptosis. Additionally, Z-FA-FMK is utilized in immunology to study immune cell functions and inflammatory responses, as it can modulate protease activity involved in these processes. Its ability to selectively inhibit specific proteases also aids in elucidating the roles of these enzymes in various diseases, including neurodegenerative disorders and infections.