Human monocyte-derived dendritic cells presented FcRn-binding NIP-gliadin-NIPhIgG1 ICs more effectively to intestinal T cells of celiac disease patients than IHH-mutated NIP-gliadin-NIPhIgG1 ICs, which strengthens the essential role of FcRn in binding Ag-IgG ICs for their antigen presentation and T cell activation. The gene discussed is FCGRT; the disease is celiac disease.