This gene encodes a member of the neurexin gene family. The products of these genes function as cell adhesion molecules and receptors in the vertebrate nervous system. These genes utilize two promoters. The majority of transcripts are produced from the upstream promoter and encode alpha-neurexin isoforms while a smaller number of transcripts are produced from the downstream promoter and encode beta-neuresin isoforms. The alpha-neurexins contain epidermal growth factor-like (EGF-like) sequences and laminin G domains, and have been shown to interact with neurexophilins. The beta-neurexins lack EGF-like sequences and contain fewer laminin G domains than alpha-neurexins. Alternative splicing and the use of alternative promoters may generate thousands of transcript variants. [From RefSeq]