Used in immunological research to study T-cell regulation and immune checkpoint pathways. Facilitates the development of therapeutic antibodies targeting immune disorders and cancers. Commonly employed in ELISA, surface plasmon resonance, and protein-protein interaction studies due to its tagged structure. Supports assay development for drug screening and characterization of binding kinetics with ligands like CD80/CD86. Valuable tool in biopharmaceutical research focused on immunotherapy.