Anti-T-box brain transcription factor 1 antibodies are used for the immunodetection of the protein encoded by the TBR1 gene. In humans, the canonical protein has a reported length of 682 amino acid residues and a mass of 74.1 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 2 different isoforms for this protein. It is notably expressed in the brain. It is known to be a transcriptional repressor involved in multiple aspects of cortical development, including neuronal migration, laminar and areal identity, and axonal projection. The gene encoding this protein is implicated in Intellectual developmental disorder with autism and speech delay. Other names for this target antigen include IDDAS, TES-56, T-box brain protein 1, T-box, brain 1, T-brain-1, and AUTS5. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.