GAD2 and small cell lung carcinoma: In a previous study involving 20 patients with anti-GABA-B receptor encephalitis, positivity for multiple antibodies was observed in seven (35%) cases; five patients with concomitant small-cell lung cancer were found to be positive for the paraneoplastic antibodies SOX1 and Ri/ANNA2, and in two patients that did not have small-cell lung cancer the GAD65 and anti-NMDAR antibodies were detected.