Genes in the T-box family play important roles in the formation of tissues and organs during embryonic development. To carry out these roles, proteins made by this gene family bind to specific areas of DNA. By attaching to critical regions near genes, the proteins help control the activity of those genes. T-box proteins are called transcription factors on the basis of this action.The T-box 1 protein appears to be necessary for the normal development of large arteries that carry blood out of the heart, muscles and bones of the face and neck, and glands such as the thymus and parathyroid. Although the T-box 1 protein acts as a transcription factor, it is not yet known which genes are regulated by the protein.The TBX1 gene is located on the long (q) arm of chromosome 22 at position 11.21, from base pair 18,118,779 to base pair 18,145,669.