Figure 4From: Genomic mapping of RNA polymerase II reveals sites of co-transcriptional regulation in human cellsLow p-value PolII and PolIIa enrichments are biased towards higher mRNA levels. The plot depicts the observed intensity from Affymetrix U133 Plus 2 chips compared with different p-values of PolII (white) and PolIIa (gray). Some genes with no significant PolII enrichment show high levels of observed intensity.Back to article page