LGI1 and small cell lung carcinoma: For example, autoantibodies to LGI1 often associate with hyponatremia but rarely associate with a tumor, GABA(B)R-antibodies frequently occur with prominent seizures and about half of the patients have a small cell lung cancer (SCLC), while patients with AMPAR-antibodies often present with limbic encephalitis or psychiatric features (1, 5, 7).