Fig. 1

Overview of the transcriptional change during the confrontation with tumor cells in the eight fibroblast samples. The principal component (PC) analysis was performed of log₂-transformed fold change expression values from Affymetrix for each gene in each of the 16 samples The text labels refer to cell sample IDs (see Methods) and are centered at the respective coordinates without offset. PCs from 1 to 4 are plotted as X and Y axes pair-wise. These four components took into account 49.9, 19.2, 11.2, and 7.4 % of the fold change variance, respectively. The analysis was meant to identify if any samples stand out compared to others in terms of overall expression