H3K4me3 signals around the transcriptions start sites of 23,849 genes. (a) Enrichment of H3K4me3 in a window surrounding the TSSs. The genes were grouped into seven clusters (I to VII) by their H3K4me3 patterns as described in the Materials and methods section. The enrichment scale is from high (yellow) to low (blue), and the red vertical line represents the TSS position. Negative x-coordinates are upstream of the TSS and positive are downstream. (b) Box plots indicating the distributions of expression levels in the seven clusters. The white box represents the expression for all genes. (c) Average H3K4me3 signal footprints for the seven clusters. The colors are as in (b).