Relative expression of genes related to estrogen receptor activity and proliferation in the mammary gland. (a), effects of estradiol (E2) and equol (EQ) treatment on expression of estrogen receptor alpha (ESR1), estrogen receptor beta (ESR2), progesterone receptor (PGR), trefoil factor 1 (TFF1), and Ki67 antigen (MKI67). (b), gene expression sorted by columnar cell lesion (CCL) status. All gene expression values were corrected for internal control gene expression and then expressed relative to control group values; lesion status effects were adjusted for any treatment group effects. * P < 0.05, ** P < 0.01, and *** P < 0.001 compared to respective control values.