As the results suggested, in breast cancer, high EZH2 expression was associated with pathological types [OR: 1.53 (95CI: 1.13-2.06); P = 0.006], histological grade [OR: 1.62 (95CI: 1.35-1.95); P = 0.000], estrogen receptor (ER) negativity [OR: 2.05 (95CI: 1.67-2.52); P = 0.000], progesterone receptor (PgR) negativity [OR: 1.42 (95CI: 1.03-1.96); P = 0.034], HER-2 positivity [OR: 1.35 (95CI: 1.08-1.69); P = 0.009], and p53 high expression [OR: 1.66 (95CI: 1.07-2.59); P = 0.024]. This evidence concerns the gene ESR1 and breast cancer.