H3K27ac - acetylation of lysine 27 of H3. Activating mark. (IHEC reference epigenome) This modification frequenty coincides with H3K4me1. It is associated with transcription initiation, open chromatin, and marks a subset of active enhancers. Enriched regions are more localized than those of H3K4me1 and it appears both in the promoter and intergenic regions of expressed genes in humans.
Click for details.