Supervised clustering with SAM/PAM subgroup–defined genes in training and test sets. A supervised clustergram of the expression of 700 genes (50 SAM-defined overexpressed and underexpressed genes from each of the 7 subgroups) across the training set of 256 cases (A) and the test set of 158 cases (B). Genes are indicated along the vertical axis and samples on the horizontal axis. The normalized expression value for each gene is indicated by a color, with red representing high expression and blue representing low expression.