Anti-H1-1 antibodies are used in the immunodetection of the protein H1.1 linker histone, cluster member. In humans, the canonical protein has a reported length of 215 amino acid residues and a mass of 21.8 kDa. Its subcellular localization is in the nucleus. It is notably expressed in the tonsil, testis, kidney, and gallbladder. A member of the Histone H1/H5 protein family, H1-1 is known to be involved with spermatogenesis. Post-translational modifications have been described, including phosphorylation. Synonyms for this target antigen include H1A, H1F1, HIST1, HIST1H1A, histone H1.1, H1 histone family, member 1, histone 1, H1a, and H1.1. H1-1 gene orthologs have been reported in the mouse, rat, bovine and chimpanzee species.