NEGR1 is a 354 amino acid protein belonging to the IgLON family and immunoglobulin superfamily. NEGR1 may play a role in cell adhesion and regenerative axon sprouting in the mammalian brain and is highly expressed in adult hippocampus, cerebrum and brainstem, with much lower levels found in cerebellum. Localizing to the cell membrane at the glycosylphosphatidylinositol anchor (GPI) anchor, NEGR1 contains three Ig-like C2-type (immunoglobulin-like) domains. NEGR1 is encoded by a gene that maps to human chromosome 1p31.1, and is one of several loci associated with body mass index (BMI), possibly contributing to the development of obesity.