In particular, breast tumors having a higher combined grade were more likely to carry the ER-α A908G mutation (odds ratio (OR) = 2.83, 95% confidence interval (CI) = 1.09 to 7.34 for grade II; OR = 1.65, 95% CI = 0.60 to 4.59 for grade III compared with grade I). This evidence concerns the gene ESR1 and breast neoplasm.