Used in research to study apoptosis signaling pathways, particularly in cancer cell death mechanisms. Binds to TRAIL (TNF-related apoptosis-inducing ligand), making it valuable for investigating targeted cancer therapies. Commonly used in protein-protein interaction studies, immunoassays, and receptor-ligand binding assays. The His tag allows for easy purification and detection, facilitating use in recombinant protein expression systems. Also employed in drug development for evaluating agonistic antibodies that trigger apoptosis in tumor cells.