A cluster of 263 differentially expressed genes depicting distinct expression profiles of MCF-7, ZR75-1, and NBr. (a) These genes formed six distinct cluster signatures (CS) between the three SAGE libraries. Each row in the cluster corresponds to a SAGE library. Percent coverage of genes within the GO terms in each CS is shown lower to the cluster. In the cluster, intense red color correlates with high expression, black indicates low expression, green is negative expression, and grey is missing expression (genes and their corresponding Unigene IDs are shown in Figure 1A a, b, additional file 3). (b) Graphs highlighting the salient distribution of genes within each of the GO terms, biological process (BP), molecular function (MF), and cellular component (CC) in the six distinct CSs (a detailed distribution of genes within the GO terms in each CS is shown in Figure 1A c: CS1-CS6, additional file 3). DAVID did not classify any genes for CC in CS2.