MUSK and myasthenia gravis: It is also noticeable that Takata and his associates generated human MuSK monoclonal autoantibodies (2 IgG4 and 1 IgG3 subclasses obtained using isolation of MuSK autoantibody-expressing B cells from MuSK antibody-positive MG patients) and showed that these antibodies inhibited AChR clustering, but enhanced MuSK phosphorylation; they suggested an alternative mechanism for inhibiting AChR clustering (Takata et al., 2019).