FCGRT and neoplasm: When ICs were formed with an engineered IgG variant known to exhibit enhanced FcRn binding with maintained pH dependency (42), antigen-specific CD8+ T-cell activation was induced at antigen concentrations 10-fold lower than that observed with native IgG IC, thereby demonstrating that targeting the immunostimulatory potential of FcRn using complexes formed with IgG variants having increased FcRn binding (15) and which are restricted to a single defined tumor antigen is a tractable and effective anti-tumor therapeutic approach (37).