Although the canonical TGF−β signaling pathway gene set (defined by KEGG pathway classification) as a whole was not significantly enriched by GSEA analysis (FDR q value of 0.97), a visual inspection of the overlaid gene expression changes onto the canonical TGF−β signaling pathway revealed several genes including SMAD2 (FDR  = 0.038) and SMAD7 (FDR  = 0.007) which were over expressed in GBM tissues compared to normal brain tissues (Figure S1). Here, SMAD2 is linked to glioblastoma.