Fig. 3.

Global differences in DNA methylation profiles between BTICs and matched GBM tumors. (A) Heatmap of sample-to-sample correlations of global DNA methylation profiles from matched GBM tumors and BTICs shows that samples largely cluster by tissue source. There was no apparent clustering by sample subtype. (B) Scatterplot of PC1 versus PC2 scores shows that the first 2 PCs are largely associated with tissue source (BTIC vs. GBM tumor) followed by sample subtype classification.