ChIP-chip of H3K4me3. (a) Enrichment of H3K4me3 within 2 kb of all human TSSs. (b) Maximum enrichment of H3K4me3 within 1 Kb of the TSS for each human gene. Genes are ordered similarly to (a). (c) Histogram of H3K4me3 signals at all human TSSs. The vertical lines correspond to thresholds used to distinguish genes containing high levels of H3K4me3 (right-side of the distribution) from genes containing low H3K4me3 levels (left side of the distribution). Genes falling between the two vertical lines are indeterminate and not designated as K4-absent or K4-present genes. The bottom panel shows an example of a gene lacking H3K4me3 (CD247), and a gene containing H3K4me3 (UCK2). (d) Maximum H3K4me3 signal at all TSSs in the five colorectal cell lines (SW480, V432, V425, V429, V441) and normal colon mucosa. Columns represent individual samples, and rows represent H3K4me3 signals at TSSs. Dark blue corresponds to high H3K4me3 enrichment; light blue corresponds to little or no enrichment.