EP300 enrichment highlights cell-type-specific enrichments. ChIP-seq signals of the transcriptional coactivator EP300 in four ENCODE cell types were overlaid on the SOM. While some of the signal is common to multiple/all cell types (orange/brown), each EP300 ChIP-seq data set highlights a different set of adjoining units on the map that is specifically enriched based on the cell type. These cell-type-specific units are also high in H3K4me1 and H3K27ac, which suggest that they hold cell-type-specific enhancers. Segments from each of the colored clusters were pooled and analyzed for functional enrichment with GREAT such as pathways (top three terms per cluster shown). While the units common to multiple cell types are enriched in genes involved in housekeeping pathways, those in the cell-type-specific regions are enriched in pathways that are known to be relevant to the biology of those cells.
