Anti-tumor protein p63 antibodies are used in the immunodetection of the protein encoded by the TP63 gene. In humans, the canonical protein has a reported length of 680 amino acid residues and a mass of 76.8 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 12 different isoforms for this protein. It is reported to be widely expressed, notably in heart, kidney, placenta, prostate, skeletal muscle, testis and thymus, although the precise isoform varies according to tissue type. A member of the P53 protein family, it is known to act as a sequence specific DNA binding transcriptional activator or repressor. Post-translational modifications have been described, including ubiquitination, sumoylation. Other names for this target antigen include B(p51A), B(p51B), EEC3, KET, LMS, NBP, OFC8, and AIS.