We performed single-cell RNA sequencing of fresh CSF and parallel blood samples of 15 patients with LGI1-AIE (n = 9) and CASPR2-AIE (n = 6) compared with control patients [multiple sclerosis (n = 15) and idiopathic intracranial hypertension (n = 18)]. The gene discussed is LGI1; the disease is multiple sclerosis.