Univariate separability of discriminative genes. Boxplots show the gene expression levels (as z-scores) between symptomatic and asymptomatic subjects for selected genes. The first figure shows the expression level for the 17 genes identified by the best pathway pairs classifier (BCell + CAM). The second figure shows the top 17 genes ranked according to univariate t-test scores. The t-test score is provided at the top of the figures for each gene. The genes from the best classifier are far less discriminative in the univariate sense than the top ranked genes, but as a group, they are more discriminative (100% vs. 89.5% classification accuracy). More than two-thirds of the genes from the best classifier fall outside of the top 500 genes ranked according to t-test.