Hierarchical clustering of GBM samples in the TCGA data set based on altered gene occurrences in the network modules identified by the edge-betweenness algorithm. The rows are samples, while the columns are 17 network modules. In the central heat map, red rectangles represent samples having altered genes in modules, while green rectangles represent samples having no altered genes in modules. The vertical blue dashed line shows the cutoff value we used to select sample clusters from the hierarchical clustering. The right-most column lists sample types: green for primary GBM samples ('No' in Table S1B in ), blue for recurrent ones ('Rec' in Table S1B in ), and red for secondary ones ('Sec' in Table S1B in ).