In other words, we can say this separate clinical entity (different terms are used: anti-MOG disease, MOG-IgG associated disorder and–most commonly nowadays–MOG antibody disease (MOGAD) is an inflammatory demyelinating condition of the CNS characterized by a mono- or multiphasic course of neurological deficits, which does not meet the criteria for typical MS or other known neuroinflammatory illnesses (especially neuromyelitis optica spectrum disorders, NMOSD) and occurs in the presence of MOG antibodies [7,41] (Figure 3). This evidence concerns the gene MOG and neuromyelitis optica.