NETO1 is a 533 amino acid protein that contains one LDL-receptor class A domain and two CUB domains and is either membrane-bound or secreted. Expressed as three alternatively spliced isoforms, the first two of which are retina-specific and the third of which is found in both retina and brain tissue, NETO1 is thought to be involved in the development and maintenance of neuronal circuitry, possibly playing a role in proper brain function. Human NETO1 shares 95% amino acid identity with its mouse counterpart, suggesting a conserved role between species. The gene encoding NETO1 maps to human chromosome 18, which houses over 300 protein-coding genes and contains nearly 76 million bases. There are a variety of diseases associated with defects in chromosome 18-localized genes, some of which include Trisomy 18 (also known as Edwards syndrome), Niemann-Pick disease, hereditary hemorrhagic telangiectasia, erythropoietic protoporphyria and follicular lymphomas.