Distribution of expression signals within genes for the three methodologies. The histograms show total signal density for 6424, 13582, and 1577 genes with detectable expression estimated by microarrays, RNA-Seq, or proteomics, respectively. In order to account for length differences among genes, for each gene we normalized the distances between the middle positions of the detected expression measurements (array probes, sequence reads, or peptides) and the 5' end of the gene by the gene length.
Fu et al. BMC Genomics 2009 10:161 doi:10.1186/1471-2164-10-161