AQP4 and neuromyelitis optica: Meanwhile, the interaction of NMO-IgG with AQP4 also triggered multiple immune-related pathways, such as chemokine/cytokine, interferon and NF-κB pathway, suggesting that the degree of NMO lesions depended on the immune microenvironment, in which multiple immune cells, including monocytes, microglia, and astrocyte, were all involved (8–10).