FCGRT and autoimmune disease: FcRn was shown to play a central role in trafficking IgGs and albumin into recycling pathways rescuing them from lysosomal degradation.14,15 Efgartigimod (ARGX-113) is a human IgG1-derived Fc fragment of the za allotype that binds to human FcRn resulting in blockage of FcRn-mediated recycling of IgGs.12,13 By inhibiting this FcRn function, efgartigimod leads to rapid degradation of IgGs, which are expected to modify IgG-driven autoimmune diseases.