Polymorphisms in hormone metabolism and growth factor genes and mammographic density in Norwegian postmenopausal hormone therapy users and non-users Ellingjord-Dale, Merete, Lee, Eunjung, Couto, Elisabeth, Ozhand, Ali, Qureshi, Samera A, Hofvind, Solveig, van Den Berg, David J, Akslen, Lars A, Grotmol, Tom, Ursin, Giske (2012-10-27)