Used in immunological research to study Fc receptor function, particularly in antibody-dependent cellular phagocytosis and immune complex clearance. The His tag allows for easy purification and detection, making it valuable in protein-protein interaction studies, ELISA, and flow cytometry applications. Commonly employed in the development and testing of therapeutic antibodies to evaluate binding affinity and effector functions. Also utilized as a capture antigen in immunoassay development for monitoring anti-drug antibodies or immune responses.