GRM1 and neuromyelitis optica: In fact, most neurological autoantibodies of proven pathogenic impact, such as antibodies to AQP4 in neuromyelitis optica [42,51-53], acetylcholine receptor in myasthenia gravis, VGCC in Lambert-Eaton syndrome [54], and mGluR1 in paraneoplastic cerebellar degeneration [11] target superstitial proteins of the plasma membrane.