Figure 1
From: RNA-Seq quantification of the human small airway epithelium transcriptome
Establishment of detection limit for gene expression for RNA-Seq assessment of gene expression of the small airway epithelium of healthy nonsmokers. A. Distribution of RPKM for exons (blue), introns (red), and intergenic regions (green). RPKM depends on the size and read numbers mapped in the region considered. The RPKM for introns and intergenic regions was calculated by selecting intronic and intergenic regions throughout the genome that match the size of the exons analyzed, i.e., the size is comparable for the introns, intergenic regions, and exons. B. Estimate of minimum detectable level of expression (RPKM = 0.125) determined from an estimate of false discovery rate (red) and false negative rate (purple) [24]. C. Average RPKM expression levels (log10). Dashed line represents the 0.125 threshold.