The homeobox is DNA sequence that is approximately 180 base pairs long that is involved in all steps of the developmental regulation of animals, fungi and plants, from embryogenesis to cell differentiation. The homeobox encodes a protein domain of about 60 amino acids, called the homeodomain, that can bind to DNA. The gastrulation brain homeobox 1 (GBX1) gene, along with another homeobox gene (EN2), maps to chromosome 7q36, and is expressed in septal and pallidal areas and in the basal forebrain cholinergic system, an area implicated in Alzheimer’s disease. The GBX1 gene encodes the GBX1 protein, which localizes to the nucleus and contains 1 homeobox DNA-binding domain.