To determine whether DC vaccination preferentially altered genes distinguishing GSCs from non-stem gliomas, Principal Component Analysis (PCA) was performed using vaccine-altered transcripts (Fig. 1A), Shh and Egfr pathway transcripts (Fig. 1A), or independent immune-modulating gene transcripts, from human GBM and mouse GL26 microarray profiles, and the first three principal components statistically generated and plotted using GeneSpring software (Fig. S2A). Here, EGFR is linked to glioblastoma.