MOG and Autoimmunity: Intriguingly, recent studies revealed that some children with NMOSD could acquire AQP4-negative autoimmunity (7, 8), indicating that myelin oligodendrocyte glycoprotein (MOG) antibody targeting MOG antigen on myelin sheaths of oligodendrocyte (9), mainly concomitant with CD4+ T cells and granulocyte infiltration, and complement deposition not observed on astrocytes or glia limitans (10), was detectable in some pediatric patients with AQP4 antibody-negative NMOSDs (11).