Anti-T-box transcription factor 4 antibodies are used for the immunodetection of the protein encoded by the TBX4 gene. In humans, the canonical protein has a reported length of 545 amino acid residues and a mass of 60.2 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 2 different isoforms for this protein. It is a reported transcriptional regulator that has an essential role in the organogenesis of lungs, pelvis, and hindlimbs. The gene encoding this protein is implicated in Ischiocoxopodopatellar syndrome with or without pulmonary arterial hypertension. Other names for this target antigen include PAPPAS, SPS, T-box transcription factor TBX4, T-box 4, T-box protein 4, and ICPPS. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.