Hierarchical clustering analysis of significant genes by treatment.

<p>Unsupervised hierarchical clustering analysis produced five main clusters. The clusters correspond to upregulated genes in all treatments (Cluster 1, n = 172), downregulated genes in all treatments (Cluster 2, n = 173), synergized downregulated genes (Cluster 3, n = 69), marked P4 downregulated genes that were moderately downregulated by estradiol-17β and estradiol-17β+progesterone (Cluster 4, n = 47), and genes that were downregulated by estradiol-17β and progesterone alone and antagonized by the combined treatment (Cluster 5, n = 24). An extensive similarity of magnitude and direction of expression can be observed between significantly regulated genes.