Lingo-4 is a 593 amino acid single-pass type I membrane protein that contains eleven LRR (leucine-rich) repeats, one Ig-like C2-type (immunoglobulin-like) domain, one LRRCT domain and one LRRNT domain. The gene that encodes Lingo-4 consists of approximately 5,891 bases and maps to human chromosome 1q21.3. Comprising nearly 8% of the human genome, chromosome 1 spans 260 million base pairs, contains over 3,000 genes and houses a large number of disease-associated genes, including those that are involved in familial adenomatous polyposis, Stickler syndrome, Parkinson’s disease, Gaucher disease, schizophrenia and Usher syndrome.