Anti-histocompatibility (minor) HA-1 antibodies are used in antigen-specific immunodetection in biological samples. The target histocompatibility (minor) HA-1 is a known alias name of the protein Rho GTPase activating protein 45, encoded by the ARHGAP45 gene in humans. This 1136-amino acid residue protein is known to be involved in GTPase activation and GPCR signaling pathways, among other biological processes. It is localized to the cytoplasm of the cell. In terms of tissue expression, it is noted to be expressed on cells of the hematopoietic lineage. Other synonyms for histocompatibility (minor) HA-1 include HA-1, HLA-HA1, and HMHA1.