Strong H3K4me3 epigenetic modification signals within the ESR1 locus in human breast adenocarcinoma MCF-7 cells. H3K4me3 signals in the MCF-7 ESR1 locus are compared with the stacked spectra of those signals in the seven other cell lines, GM12878 (human lymphoblastoid cell), H1-hESC (H1-human Embryonic Stem Cell), HSMM (Human Skeletal Muscle Myoblast cell), HUVEC (Human Umbilical Vein Endothelial Cell), K562 (human immortalised myelogenous leukemia cell), NHEK (Normal Human Epidermal Keratinocytes), and NHLF (normal human lung fibroblasts). The y-axis indicates the intensity of the epigenetic modification H3K4me3 at each genomic position.