Functional analysis of genes selected in each step.

(A) To determine the statistical significance of selected genes, we counted the number of genes identified in each step of our analysis. (B) Utilizing a set of 93 genes that are implicated in GBMs as of Aceview we calculated the statistical significance of the overlap (numbers in parentheses) with a hypergeometric distribution. We found that the significance increased, applying the steps in our approach. (C) Calculating p-values with a modified Fisher's exact test, we obtained a similar result for a set of glioma genes as of DAVID as well.