In the context of multiple FBDS that appear to be unrelenting and limbic encephalitis with a history of cancer, an increased likelihood that the cause is either autoimmune or paraneoplastic should be entertained, and clinicians should be cautious not to rule out LGI1 as a cause of seizures or encephalitis based solely on a negative CSF antibody result because LGI1 antibodies can be absent in spinal fluid in up to 50% of patients, even in cases that are clearly diagnosed using cell-based assays [4]. The gene discussed is LGI1; the disease is viral encephalitis.