It also appeared to be stronger in estrogen receptor (ER)+ progesterone receptor (PR)− (pooled OR: 1.47; 95% CI: 0.94, 2.3), PR− (pooled OR: 1.3; 95% CI: 0.75, 2.26), ER−PR− (pooled OR: 1.25; 95% CI: 0.77, 2.02), and ER− (pooled OR: 1.15; 95% CI: 0.94, 1.42) than that in ER+ (pooled OR: 1; 95% CI: 0.93, 1.07), PR+ (pooled OR: 1.01; 95% CI: 0.78, 1.31), and ER+PR+ (pooled OR: 1.02; 95% CI: 0.79, 1.32) for breast cancer. Here, ESR1 is linked to breast cancer.