Pathways are altered after tumor engraftment and then stable over passages. (A) Each heatmap represents the standardized expression levels of the core genes (according to GSEA) from the functional groups significantly altered in PDX models. For each tumor we have three sampling times: F0 (passage 0, original primary tumor), F5 (fifth passage) and F10 (tenth passage). Color code: red, high; grey, medium; blue, low. (B) Barplot showing the GSEA normalized enrichment score (NES) for each functional group obtained in the three group comparisons: F0 versus F5 (left), F5 versus F10 (middle) and F0 versus F10 (right). The color code used is the same as in Figure 3. Significantly enriched functional groups (FDR <0.005) are indicated with three asterisks.