Figure 3. Concordance between DNA copy number and gene expression across chromosome 17. DNA copy number alteration (upper panel) and mRNA levels (lower panel) are illustrated for breast cancer cell lines and tumors. Breast cancer cell lines and tumors are separately ordered by hierarchical clustering in the upper panel, and the identical sample order is maintained in the lower panel. The 354 genes present on the microarrays and mapping to chromosome 17, and for which both DNA copy number and mRNA levels were determined, are ordered by position along the chromosome; selected genes are indicated in color-coded text (see Fig. 2 legend). Fluorescence ratios (test/reference) are depicted by separate log2 pseudocolor scales (indicated).