Progesterone receptor is expressed as two major isoforms, PR-A (81kDa) and PR-B (116kDa). Expression of progesterone receptor has been suggested to reflect a intact estrogen regulatory machinery and therefore predict better clinical response to endocrine therapy than ER alone.

Store the Progesterone Receptor antibody at 2-8°C (with azide) or aliquot and store at -20°C or colder (without azide).