Studies have shown that in the MCF-7 breast cancer cell line, BPA binds with similar affinities to ERα (IC50 ~6.0 × 10−6M) and ERβ (IC50 ~6.5 × 10−6M); elevates transcriptional activity at estrogen response elements; and exerts proliferative effects (25). This evidence concerns the gene ESR1 and breast carcinoma.