Differentially expressed genes by E2 and EGF compared to controls and effect of TAM. (A). Number of genes significantly up- or down-regulated (>1.5×) in MCF7-EGFR cells 6 hr after treatment with E2 (10 nM), EGF (100 ng/ml) or E2 + EGF, with and without 10 μM TAM, compared to controls as determined by microarray gene expression analysis. (B) The percentage inhibition by TAM for genes >1.5× fold up regulated by exposure to E2 or EGF. (C) The percentage inhibition by TAM for genes >1.5× fold dow nregulated by exposure to E2 or EGF. Also shown is the inhibition by TAM of the subsets of E2 or EGF regulated genes that are also regulated by E2 or EGF under the condition of combined exposure to E2 + EGF.