Periependymal lesions in NMO suggest that the sub-ventricular niche may be compromised, lacking the ability to produce new cells for tissue repair.48 Sera from NMO patients can enhance the production by SVZ neurospheres of GFAP+ cells but reduce that of Tuj1+ (neurons) and Olig2+ (oligodendrocyte precursor cell).37 Similarly, we found that NMO-IgG activates the proliferation of sub-ventricular cells and of qNSCs. This evidence concerns the gene OLIG2 and neuromyelitis optica.