Hormone therapy effects on gene markers related to ER expression and activation. (a) Hormone therapy effects on gene markers related to oestrogen receptor (ER) activation; (b) ER expression; (c) estradiol synthesis and bioactivation; and (d) estradiol deactivation. mRNA expression levels were determined by quantitative PCR. Vertical lines indicate 90% confidence interval. Letters indicate significant differences compared with control (P < 0.05a, P < 0.01b, P < 0.001c) and conjugated equine estrogens plus medroxyprogesterone acetate (CEE + MPA) (P < 0.01d, P < 0.001e) groups.