The leucine-rich (LRR) repeat is a 20-30 amino acid motif that forms a hydrophobic a/∫ horseshoe fold, allowing it to accommodate several leucine residues within a tightly packed core. All LRR repeats contain a variable segment and a highly conserved segment, the latter of which accounts for 11 or 12 residues of the entire LRR motif. Leucine-rich glioma-inactivated protein 3 (LGI3), also known as LGI1-like protein 4 (LGIL4) or leucine-rich repeat LGI family member 3, is a 548 amino acid secretory protein. LGI3 contains five LRR repeats and seven EAR repeats. Widely expressed, with highest levels in brain and lung, LGI3 has been shown to colocalize with endocytosis-associated proteins, lipid raft markers, and Syntaxin. The gene encoding LGI3 maps to chromosome 8p21.3.