Mammary gland growth and development from the postnatal period to postmenopause: ovarian steroid receptor ontogeny and regulation in the mouse.

Ovarian steroid hormones play a critical role in regulating mammary gland growth and development. The mammary gland sequentially acquires and cyclically exhibits proliferative responses to estrogen and/or progesterone from birth to postmenopause. The focus of this review is to present our current understanding of estrogen and progesterone receptor distribution in epithelial and stromal cells and their functions in relation to mammary gland development. Insights gained from the study of the normal mammary gland are relevant to our understanding of the conditions which may predispose women to the development of breast cancer as well as to alterations in hormonal regulation that occur in breast cancer.