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Key T, Appleby P, Barnes I, Reeves G; Endogenous Hormones and Breast Cancer Collaborative Group.Key T, et al.J Natl Cancer Inst. 2002 Apr 17;94(8):606-16. doi: 10.1093/jnci/94.8.606.J Natl Cancer Inst. 2002.PMID: 11959894