Venn diagrams demonstrate the overlap/lack of overlap between prognostic biomarkers. (a) Blue circles stand for the genes identified as significant in stratifying patients into survival groups in TCGA. Red circles are genes identified in Duke set #1 and green circles are genes identified in Duke set #2. The shared colored circles are genes shared between datasets. While some genes are shared between two groups, none is shared among all three datasets. (b-d) Venn diagrams for the gene set signature analysis. In contrast, (e) shows the same analyses performed via pathway metrics. One pathway (PDGF signaling pathway) is shared among the three datasets and demonstrates the robustness of the pathway approach.