Used in immunological research to study antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis. Serves as a binding target for therapeutic monoclonal antibodies to evaluate Fc effector functions. Employed in surface plasmon resonance (SPR) and ELISA assays to measure antibody affinity and specificity. Supports development and optimization of antibody-based drugs, especially in oncology and autoimmune disease therapeutics. The His tag facilitates easy purification and immobilization on nickel-based surfaces.