The data revealed that, after incubation of astrocytes with CON-IgG, the AQP4 was uniformly distributed on the cytomembrane of astrocytes, whereas NMO-IgG induced the aggregation of AQP4 on the cytomembrane of astrocytes into granules and internalization to the cytoplasm (Figure 3A). The gene discussed is AQP4; the disease is neuromyelitis optica.