(a) Heatmap shows similarity scores (pair-wise Jaccard distances) for accessibility between all GM12878 and K562 cells measured on the union set of DHSs from GM12878 and K562 cells. Cells were grouped based on unsupervised hierarchical clustering. (b) Average GpC methylation at the DHSs from GM12878 cells and K562 cells, respectively, was calculated for all individual GM12878 and K562 cells. The resulting two values for GpC methylation are displayed for each cell. While the average methylation levels at K562 DHSs for both cell types appear similar, GM12878 and K562 are separable based on these data when accounting for different levels of genome-wide GpC methylation in GM12878 and K562 cells. Importantly, for cells from either cell type the methylation levels are higher in the DHSs of the cell type of origin than in the DHSs of the other cell type. (c) Heatmap shows correlation coefficients between all GM12878 and K562 cells for pair-wise comparison of CpG methylation levels. Genome was divided into 10 kb bins and only bins with sufficient coverage in both cells were used for a given pair (> = 20 covered CpGs). Cells were grouped based on unsupervised hierarchical clustering.