Fig. 4

Relationship between enrichment ratio and false discovery rate (FDR) representing the results of overrepresentation of differentially expressed genes (DEGs) using A 50 Hallmark gene sets from the Human Molecular Signatures Database with the Senescence gene set and B ENCODE transcription factor target gene sets after 4 weeks exposure to 30 µg/ml diesel exhaust particles (DEP). The intensity of the purple color indicates the number of DEGs included in the gene set. The enrichment ratio reflects the number of DEGs included in the gene set of interest divided by the expected number of genes in the gene set, calculated based on the reference genes that passed the quality filter