Figure 1

Overview of the study approach.

For a gene involved in a pathway (pathway gene), target genes of transcription factors involved in the same pathway were considered to be target genes of the pathway genes. Even if there are no expression differences between the pathway gene (A) and target gene (B) in two phenotypic groups, the correlation between them (C) can still differ. (D) EGFR target genes were significantly correlated only in drug-sensitive patients. Each rectangle represents EGFR target genes and color indicates the portion of datasets in which the target gene had a Spearman's rank order correlation coefficient (P < 0.05) with EGFR in terms of mRNA expression level. (E) Target genes of a pathway gene were defined as target genes of transcription factors involved in the same pathways of the pathway gene. For each phenotypic group, we calculated the ratio of target genes with a significant expressional correlation with the pathway gene over all target genes, which is termed as the significance rate (SR) of the pathway gene. The ratio of small SR over large SR is restricted to range [0, 1] and termed as the significance score (SS) of the pathway gene.