Hierarchical clustering of the colon tumor samples and the 1722selected genes A) Classification of the 89 (sample CT102 isreplicated) tumor samples in four main clusters. Yellow shadow:Cluster-1, Low-stroma-subtype; green: Cluster-2,Immunoglobulin-related-subtype; red: Cluster-3, High-stroma-subtype;blue: Cluster-4, Mucinous-subtype; and brown: Cluster-5, unclassifiedsamples. Dukes’ stages are specified below the tree. B)Each column in the heatmap represents one sample and each row representsone gene. The relative levels of gene expression within each sampleagainst the reference pool are illustrated according to the color scalebar (4 fold induction (red); -4 fold inhibition (blue)). The principalsections of the graph that distinguish between clusters are indicatedwith a color bar on the right. The green bar localizes gene 270 to gene523, a group of 253 genes with low expression in cluster 1 and highexpression in cluster 3; the red bar corresponds to genes 524 to 664 agroup of 140 genes, whose expression is lower in cluster 1. Blue barlocalizes genes 997 to 1102 a group of 105 genes with a higherexpression in cluster 4 compared to 3. Yellow bar localizes genes from1247 to 1352 a group of 105 genes specific for cluster 2 (seeSupplemental data for the list of the 1722 genes).