Anti-proliferating cell nuclear antigen antibodies are used for the immunodetection of the protein encoded by the PCNA gene. In humans, the canonical protein has a reported length of 261 amino acid residues and a mass of 28.8 kDa. Its subcellular localization is in the nucleus. A member of the PCNA protein family, it is reported to be an auxiliary protein of DNA polymerase delta and epsilon, is involved in the control of eukaryotic DNA replication by increasing the polymerase's processibility during elongation of the leading strand. Other names for this target antigen include DNA polymerase delta auxiliary protein, cyclin, and ATLD2. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. Over 4700 citations in the literature describe the use of proliferating cell nuclear antigen antibodies in research. Western Blot is a widely used application for these antibodies. Immunofluorescence and Immunohistochemistry are also common applications.