Anti-T-box transcription factor 21 antibodies are used for the immunodetection of the protein encoded by the TBX21 gene. In humans, the canonical protein has a reported length of 535 amino acid residues and a mass of 58.3 kDa. Its subcellular localization is in the nucleus. It is reported to have t-cell specific expression. It is noted to be involved in the regulation of transcription and the regulation of cell differentiation. Post-translational modifications have been described, including ubiquitination and phosphorylation. The gene encoding this protein is implicated in Asthma. Other names for this target antigen include T-PET, T-bet, TBET, TBLYM, T-box transcription factor TBX21, T-box 21, T-box expressed in T cells, and IMD88. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.