The progesterone receptor is a member
of the steroid-receptor family. Steroid hormones bind to intracellular
receptors, and these receptors can bind to DNA and regulate gene expression
directly. Research has shown PR to reflect intact estrogen regulatory machinery.
PR staining patterns observed include: ER+ and PR+, ER+ and PR-, ER and PR+, and
ER- and PR-. This PR antibody provides excellent staining in formalin-fixed
paraffin-embedded tissues and has been shown to have superior sensitivity to
most progesterone receptor antibodies.