Prevalence of mammary epithelial lesions following control (con), estradiol (E2), and equol (EQ) treatment. CCC, columnar cell change; CCH, columnar cell hyperplasia; ADH, atypical ductal hyperplasia; ALH, atypical lobular hyperplasia. Numbers on bars indicate the number of animals identified with each type of lesion. * P < 0.05 vs. control group by Fisher’s exact test.