Leucine-rich, glioma inactivated 1, also known as LGI1, is a protein which in humans is encoded by the LGI1 gene. This gene encodes a member of the secreted leucine-rich repeat (LRR) superfamily and shares homology with members of the SLIT protein family. The encoded protein may regulate the activity of voltage-gated potassium channels and may be involved in neuronal growth regulation and cell survival. This gene is rearranged as a result of translocations in glioblastoma cell lines, and it is frequently down-regulated or rearranged in malignant gliomas. Mutations in this gene result in autosomal dominant lateral temporal epilepsy. Alternative splicing results in multiple transcript variants.