Anti-PAXX non-homologous end joining factor antibodies are used for the immunodetection of the protein encoded by the PAXX gene. In humans, the canonical protein has a reported length of 204 amino acid residues and a mass of 21.6 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 2 different isoforms for this protein. A member of the XRCC4-XLF protein family, it is known to be involved with DNA damage pathways. Post-translational modifications have been described, including phosphorylation. Other names for this target antigen include XRCC4-like small protein, paralog of XRCC4 and XLF, and protein PAXX. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.