Anti-IMP U3 small nucleolar ribonucleoprotein 4 antibodies are used for the immunodetection of the protein encoded by the IMP4 gene. In humans, the canonical protein has a reported length of 291 amino acid residues and a mass of 33.8 kDa. Its subcellular localization is in the nucleus. It is a known component of the 60-80S U3 small nucleolar ribonucleoprotein (U3 snoRNP). Other names for this target antigen include IMP4 homolog, U3 small nucleolar ribonucleoprotein, IMP4, U3 small nucleolar ribonucleoprotein, homolog, U3 snoRNP protein 4 homolog, and U3 small nucleolar ribonucleoprotein protein IMP4. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.