The leucine-rich (LRR) repeat is a 20-30 amino acid motif that forms a hydrophobic Alpha/Beta 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. The LRRTM protein family plays a role in the regulation of various cellular events during nervous system development. Localizing predominantly to the nervous system, LRRTM family members are known to exhibit synaptogenic activity. LRRTM2 (leucine rich repeat transmembrane neuronal 2), also known as LRRN2, is a 516 amino acid single-pass type I membrane protein involved in the development maintenance of the vertebrate nervous system. Expressed in kidney and neuronal tissues, LRRTM2 contains ten LRR repeats and belongs to the LRRTM family. LRRTM2 is encoded by a gene that maps to human chromosome 5q31.2.