COX4NB (Neighbor of COX4) is a 210 amino acid protein encoded by the human gene COX4NB. COX4NB belongs to the UPF0172 (NOC4) family and is found on chromosome 16, adjacent to the gene that encodes COX4. The GAN gene is located on chromosome 16 and, with mutation, may lead to giant axonal neuropathy, a nervous system disorder characterized by increasing malfunction with growth. The rare disorder Rubinstein-Taybi syndrome is also associated with chromosome 16 through the CREBBP gene which encodes a critical CREB binding protein. Crohn’s disease is a gastrointestinal inflammatory condition associated with chromosome 16 through the NOD2 gene. An association with systemic lupus erythematosis and a number of other auto-immune disorders with the pericentromeric region of chromosome 16 has led to the identification of SLC5A11 as a potential autoimmune modifier.