Figure 2. Hierarchical clustering of gene expression data from van't Veer et al. A. The full cluster of 461 genes across 97 sporadic tumors. B.Experimental dendrogram displaying similarities between the tumors. Branches are color-coded according to the subtype to which the corresponding tumor sample shows the highest correlation. Tumors with low correlation (< 0.1) to a specific subtype are indicated by gray branches. C. Gene cluster associated with the luminal subtype A. D. Gene cluster containing the ERBB2 oncogene and co-clustered genes. E. Group of genes that tend to be highly expressed in luminal subtype B tumors. F. Gene cluster characteristic of basal tumors. Scale bar represents fold change for any given gene relative to the median level of expression across all samples. (See also Figure 7, which is published as supporting information).