Anti-H2BC21 antibodies are used in the immunodetection of the protein H2B clustered histone 21. In humans, the canonical protein has a reported length of 126 amino acid residues and a mass of 13.9 kDa. Its subcellular localization is in the nucleus and chromosomes. It is notably widely expressed in many tissue types. A member of the Histone H2B protein family, H2BC21 is an important component of nucleosome. Post-translational modifications have been described, including glycosylation, ubiquitination and phosphorylation. Synonyms for this target antigen include H2B, H2B-GL105, H2B.1, H2BE, H2BFQ, H2BGL105, H2BQ, and GL105. H2BC21 gene orthologs have been reported in the mouse, rat, bovine and chimpanzee species.