MOG and neuromyelitis optica: Recently, an increasing number of studies have confirmed that quantitative or functional impairment of Bregs and Tregs, or deregulation of Tfh, is related to many neurological autoimmune diseases, such as multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), myelin oligodendrocyte glycoprotein antibody disease (MOG-AD), and myasthenia gravis (MG) [14–20].