Question: What are estrogen and progesterone hormone receptors?
Answer: Well, we can really imagine that what these, what we call "proteins," are inside the breast cancer cell, these particular proteins are really like locking mechanisms. And the estrogen is the key. Estrogen binds to the estrogen receptor and unlocks a mechanism to cause regulated growth in normal tissues but unregulated growth in something like a breast cancer. It's the same for the progesterone receptor. The progesterone receptor is a key specifically for that protein that will switch on all of the events regulated by progesterone in that particular organ.
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