ESR1 and breast cancer: Interestingly, the association was almost the same regarding menopause status (OR 0.76, 95% CI 0.63–0.92 in premenopausal vs. 0.75, 95% CI 0.62–0.90 in postmenopausal) and estrogen receptor (0.77, 95% CI 0.62–0.95 in ER+ vs. 0.77, 95% CI 0.52–1.15 in ER-), suggesting that menopause status and estrogen receptor had little effect on the correlation between isoflavone and breast cancer risk.