IgG-based therapeutic antibodies are increasingly adopted for diverse human diseases, such as cancer and autoimmune disorders displaying remarkable therapeutic performance. A key factor in their success lies in the extended half-life of IgG molecules, which is regulated by the pH-dependent interaction between IgG and neonatal Fc receptor (FcRn). This interaction prevents lysosomal degradation of IgG. Despite the frequent use of humanized rodent models expressing human FcRn (hFcRn) in preclinical...