AQP4 and neuromyelitis optica: For further studies, peptides were first pre-selected based on high binding rates to NMO-IgG in ELISA (Fig. 2), on their interference with phage-binding to NMO-IgG (Fig. 2), or on their mapping to extracellular loops of human AQP4 (pdb 3GD8) (Fig. 2), before we tested whether the selected peptides represent true mimotopes able to compete with conformational AQP4 epitopes on human AQP4-transfected HEK293 cells for NMO-IgG binding (Fig. 2).