Hormone replacement therapy with estrogen or estrogen plus medroxyprogesterone acetate is associated with increased epithelial proliferation in the normal postmenopausal breast. - Hofseth,L.J.; Raafat,A.M.; Osuch,J.R.; Pathak,D.R.; Slomski,C.A.; Haslam,S.Z. (J Clin Endocrin Metab, 1999)