GAD2 and cancer: Patients with high serum and cerebrospinal fluid (CSF) titers of anti-GAD65 antibodies (Abs) have been proven to be clinically heterogeneous, including those with stiff-person syndrome (SPS), cerebellar ataxia (CA), limbic encephalitis (LE), nonlimbic autoimmune encephalitis (AE), autonomic neuropathy and other multifarious neurological disorders [5, 6].