In order to identify module-specific a priori gene sets, the leading edge analysis (LEA) tool within GSEA software was applied. The leading edge genes are the subset of genes in the gene list preceding the point of maximum ES, i.e. the genes that contributed to the net increases in ES and constituted the significant enrichment of the a priori gene set. After identifying the LE genes for each ranked gene list, we selected those a priori gene sets containing at least one module member gene to be module-specific gene sets.
