Anti-H2A clustered histone 19 antibodies are used for the immunodetection of the protein encoded by the H2AC19 gene. Other names for this target antigen include histone 2, H2aa4, histone H2A/r, histone cluster 2 H2A family member a4, histone cluster 2, H2aa4, and histone H2A type 2-A. Gene orthologs have been identified in the mouse and rat species.