CCDC89 is a 374 amino acid cytoplasmic and nuclear protein that interacts with HRT1 and belongs to the CCDC89 family. The gene that encodes CCDC89 consists of more than 2,000 bases and maps to human chromosome 11q14.1. Chromosome 11, which comprises approximately 4% of the human genome, is considered a gene and disease association-dense chromosome. The chromosome 11 encoded Atm gene is important for regulation of cell cycle arrest and apoptosis following double strand DNA breaks. Atm mutation leads to the disorder known as ataxia-telangiectasia. The blood disorders Sickle cell anemia and thalassemia are caused by HBB gene mutations, while Wilms' tumors, WAGR syndrome and Denys-Drash syndrome are associated with mutations of the WT1 gene. Jervell and Lange-Nielsen syndrome, Jacobsen syndrome, Niemann-Pick disease, hereditary angioedema and Smith-Lemli-Opitz syndrome are also associated with defects in chromosome 11-encoded genes.