CLUAP1 (Clusterin associated protein 1) is a 413 amino acid nuclear protein that exists as two alternatively spliced isoforms that interact with Clusterin. CLUAP1 is suggested to play a role in apoptosis and cell proliferation, and is expressed in testis, thrachea and thyroid, with low levels found in adrenal gland and spinal cord. The gene encoding CLUAP1 maps to human chromosome 16, which encodes over 900 genes and comprises nearly 3% of the human genome. 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, as is Crohn's disease, which is a gastrointestinal inflammatory condition.