ATP1B2 and myeloid sarcoma: According to the 2015 diagnostic criteria [4], these diseases are: (i) characterized by longitudinally extensive transverse myelitis (TM), optic neuritis (ON), and brainstem dysfunction, among other symptoms; (ii) they are positive for αAQP4 and/or αMOG; and (iii) are a distinct entity from multiple sclerosis (MS) [5–7], thus requiring its exclusion.