Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has emerged as a distinct autoimmune demyelinating disorder, characterised by clinical, radiological, and immunopathological features that differentiate it from Multiple Sclerosis (MS) and AQP4+ neuromyelitis optica spectrum disorder (AQP4+NMOSD). The gene discussed is AQP4; the disease is myeloid sarcoma.