Ac-IETD-AFC is widely used as a fluorogenic substrate in biochemical research to study caspase-8 activity, a key enzyme involved in apoptosis (programmed cell death). It is particularly useful in assays designed to measure the activation and inhibition of caspase-8 in cellular and enzymatic studies. When cleaved by caspase-8, the substrate releases a fluorescent compound, 7-amino-4-trifluoromethylcoumarin (AFC), which can be detected and quantified using fluorescence spectroscopy. This allows researchers to monitor caspase-8 activity in real-time, providing insights into apoptotic pathways and the effects of potential therapeutic agents. Its high sensitivity and specificity make it a valuable tool in drug discovery and cancer research, where understanding apoptosis regulation is critical.