Relationship between core promoter type and gene length. A-C. Gene sets which differ in their core promoter, as described in the text, were analyzed for the length of their genes (A), mRNA (B) and introns (C). The boxplots present the median, 25% and 75% quartile values that were calculated from 527 TATA, 694 TATA-1, 3916 TATA-2 and 9491 TATA-less genes. D. The p-values of the differences in the median value between each two gene sets as indicated. NS is non-significant difference (p > 0.05).