Though with tamoxifen, EGCG (25 mg kg−1) had lowered the negative estrogen receptor (ER-) in breast cancer cell lines, as it was expected to decrease protein expression of the epidermal growth factor receptor (EGFR), mammalian target of rapamycin (mTOR), and cytochrome P450 family 1 subfamily B member 1 (CYP1B) [126]. This evidence concerns the gene ESR1 and breast carcinoma.