Hierarchical clustering from six samples, based on the differentially expressed 115 probesets. RNA samples from three independent biological replicate studies of RKO cells transfected with either PcDNA3.1(IGFBP-rP1) (three single cell clones, named RP5, RP6, RP7)or with either empty vector control (three single cell clones, named as EV5, EV6, EV7) were labeled and hybridized to Affymetrix U133 plus 2.0 GeneChips. Gene expression data were analyzed with GCOS1.2. One hundred and fifteen differentially expressed probesets according to a signal intensity cutoff protocol described in the text were selected for hierarchical clustering using GeneSpring 7.2. Genes with similar expression profiles were grouped together and the resulting gene tree is shown. Strong replicate clustering was shown. The left three lines mean the results in EV 5, EV6, EV7. The right three lines mean the results inRP5, RP6, RP7. Red represents up-regulation, green represents down-regulation. Black indicates no change. Quantitative data for the magnitude of each gene expression change, together with gene descriptions are shown in Table 4.