Heatmap of hierarchical clustering. The vertical hierarchical cluster shows that the CEU (black) and Asian (red) populations can be separated by clustering their genotypes as shown in the horizontal hierarchical tree. Upper heatmap: black shading represents individuals homozygous for the upregulated allele, and gray shading represents heterozygous. White shading indicates individuals homozygous for the downregulated allele. The lower heatmap represents expression of the genes corresponding to the eSNPs in the upper heatmap; intensity of red is proportional to degree of expression above the mean, and intensity of green is proportional to degree of expression below the mean.