In this issue, McKeon et al1 report that 10 of 81 patients with stiff-man syndrome from the Mayo Clinic in Rochester, Minnesota, had serum and/or cerebrospinal fluid IgG antibodies that bound to fixed, permeabilized HEK293 cells (an immortalized human kidney line) that had been transfected to express the glycine receptor α1 (GlyRα1) subunit protein. Screening of serum samples from 100 controls with a neurological disease and 20 normal controls yielded only 1 patient positive for GlyRα1, a patient with optic atrophy and multicentric white matter disease.