Anti-neuraminidase 4 antibodies are used in the immunodetection of the protein encoded by the NEU4 gene. In humans, the canonical protein has a reported length of 484 amino acid residues and a mass of 51.6 kDa. Its subcellular localization is in the mitochondria, ER, and cell membrane. Alternative splicing is reported to yield 3 different isoforms for this protein. A member of the Glycosyl hydrolase 33 protein family, it is a reported exo-alpha-sialidase that catalyzes the hydrolytic cleavage of the terminal sialic acid (N-acetylneuraminic acid, Neu5Ac) of a glycan moiety in the catabolism of glycolipids, glycoproteins and oligosacharides. Post-translational modifications have been described, including N-glycosylation. Other names for this target antigen include N-acetyl-alpha-neuraminidase 4, neuraminidase 4 (sialidase), and sialidase-4.