Used in immunological research to study immune checkpoint pathways, particularly in modulating T-cell and dendritic cell activity. Plays a role in developing therapies for autoimmune diseases and cancer immunotherapy by regulating immune tolerance. Commonly employed in protein-protein interaction assays, ELISA, and flow cytometry to detect binding partners and evaluate receptor-ligand interactions. Also utilized in the development of monoclonal antibodies and biologics targeting immune inhibitory receptors.