ESR2 and breast cancer: As for the ESR2 polymorphism rs3020449, an increased risk of BC was found in heterozygous model (CT vs. TT: OR = 1.58, 95% CI = 1.21–2.06), dominant model (CT/CC vs. TT: OR = 1.54, 95% CI = 1.20–1.98), and overdominant model (TT/CC vs. CT: OR = 1.48, 95% CI = 1.15–1.90).