Of note, rozanolixizumab, a monoclonal antibody blocking the neonatal Fc receptor, which has already been approved for the treatment of myasthenia gravis (MG) and is currently being investigated in a phase-III study in MOG-EM/MOGAD, has been reported to preferentially lower IgG3 serum levels [21]. Here, IGHG3 is linked to myasthenia gravis.