Similarity between SWT and E2 treatment on “estrogen-responsive genes”. (A) Scatterplot graph shown as the comparison of gene expression profiles of 45 selected probes between E2 and SWT treatment at various concentrations (SH, SM and SL). The axes show log2 FC calculated for each of the treatment condition. The Spearman correlation coefficient (R) between two profiles was calculated for each graph. The E2-up-regulated probes are red; E2-down-regulated probes are blue. CYP1A1 on the plots is highlighted because it is down-regulated by E2 (blue) but up-regulated by SWT. P < 0.0001 for all the correlations. (B) The hierarchical clustering analysis and heatmap of the correlation coefficients between the gene expression profiles based on log2 FC for each treatment group. A high correlation coefficient, colored in red in the heatmap, means that the gene expression profiles from two microarrays are very similar. The analysis focusing on 45 estrogen-responsive genes shows that all the SWT treatment concentrations showed higher similarity with E2 treatment.