In addition, the rs3798758 A allele of ESR1 was associated with an increased risk of breast cancer (per-allele OR = 1.19, 95% CI: 1.04 to 1.37, P = 0.013), whereas the rs2228480 A allele of ESR1 was associated with a decreased risk (per-allele OR = 0.84, 95% CI: 0.72 to 0.98, P = 0.025). This evidence concerns the gene ESR1 and breast cancer.