Anti-IMP3 antibodies are used in the immunodetection of the protein IMP U3 small nucleolar ribonucleoprotein 3. 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 a the Universal ribosomal protein uS4 protein family, IMP3 is a known component of the 60-80S U3 small nucleolar ribonucleoprotein (U3 snoRNP). Synonyms 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.