Case-matched ratios-race group tests for specific expression trends. A cluster gram is shown in Figure 5. Those genes found to be differentially expressed were clustered using hierarchical cluster analysis to visualize the pattern of gene expression for each sample. Samples which represents the gene expression pattern that results when CA tumor/CA normal ratio is compared to AA tumor/AA Normal. The heat map indicates that blue represents highly expressed genes, while yellow represents under expressed genes; the black color on the heat map represented equal expression relative to control.