MOG stands for Myelin Oligodendrocyte Glycoprotein, which is a glycoprotein believed to be important in the myelination of nerves in the central nervous system (CNS) . It is a protein that is located on the surface of myelin sheaths in the CNS. MOG is speculated to serve as a necessary "adhesion molecule" to provide structural integrity to the myelin sheath and is known to develop late on the oligodendrocyte. MOG is a target of the immune system in MOG antibody disease (MOGAD), which is a neurological, immune-mediated disorder in which there is inflammation in the optic nerve, spinal cord, and/or brain. The diagnosis of MOGAD is confirmed when MOG antibodies in the blood are found in patients who have repeated inflammatory attacks of the central nervous system. The specific symptoms and severity of MOGAD can vary from one individual to another, but include issues with vision, symptoms associated with damage to the spinal cord, as well as seizures.