Anti-IMP U3 small nucleolar ribonucleoprotein 3 antibodies are used for the immunodetection of the protein encoded by the IMP3 gene. In humans, the canonical protein has a reported length of 184 amino acid residues and a mass of 21.9 kDa. Its subcellular localization is in the nucleus. A member of the Universal ribosomal protein uS4 protein family, it is a known component of the 60-80S U3 small nucleolar ribonucleoprotein (U3 snoRNP). Other names for this target antigen include C15orf12, MRPS4, U3 small nucleolar ribonucleoprotein protein IMP3, IMP3, U3 small nucleolar ribonucleoprotein, homolog, U3 snoRNP protein 3 homolog, and BRMS2. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.