Progesterone Receptor (PR)

PR is an estrogen regulatory protein with two isoforms, PGRα and PGRβ, with molecular weight of 94KDa and 114KDa, respectively. Its physiological function is to act as a ligand-activated transcription factor in normal endometrial and breast epithelial cells. PR expression is documented in variety of breast and ovarian and can be used as a reference for endocrine therapy of breast cancer.