Distance color map based on the quantitative expression of 167 genes selected by ANOVA filtering. Ninety-five B-lineage acute lymphoblastic leukemia samples were analyzed using high-density oligonucleotide microarrays. Color maps are used to display distance matrices between samples. The distance between two samples is computed as 1 minus the correlation between the standardized expression values of the samples. The magnitude of distance is represented in color with a continuous spectrum from blue (close) to red (far). The diagonal of the distance map represents the distance of n samples to itself, 0, and is colored in the deepest shade of blue. For further details, please see Chiaretti et al. on page 7209 in this issue.