A portion of amino acids 483-571 was used as the immunogen for the PGR antibody.
This MAb is specific to PR/PGR and shows minimal cross-reaction with other members of the family. PR is expressed as two major isoforms, PR-A (81kDa) and PR-B (116kDa). Expression of PgR has been suggested to reflect an intact estrogen regulatory machinery and therefore, predict better clinical response to endocrine therapy than ER alone. It is excellent for immunohistochemical staining of formalin/paraffin tissues.