Hierarchical cluster analysis of pathway and regulatory elements. This hierarchical cluster analysis shows the regulatory elements predicted to have a general activity in the data set, i.e. in at least 4 of the 9 groups. Regulatory elements are colored according to the activation state. Red color indicates activation, while green color indicates inhibition. Dark and pale red/green colors indicate high and low significance of change, respectively. 33 pathways were found to be significantly regulated by the chemicals. These were clustered and colored from white to blue according to the involvement grade of the pathway, as estimated by the number of regulated molecules. The chemical groups were ordered according to their Local Lymph Node Assay potency with the most potent to the left and least potent to the right in the picture. The complete data set is given in Additional file 1.