progesterone receptors

Definition of progesterone receptor
National Cancer Institute

progesterone receptor

(proh-JES-teh-rone reh-SEP-ter)
A protein found inside the cells of the female reproductive tissue, some other types of tissue, and some cancer cells. The hormone progesterone will bind to the receptors inside the cells and may cause the cells to grow. Also called PR.

Source: NCI Dictionary of Cancer Terms