CAGE samples corresponding to CD4+, CD8+, B cells, NK cells and monocytes were selected in triplicates from among the set of primary cell samples. Based on the total set of 43,011 permissive enhancers, a subset of 6,609 blood-expressed enhancers was defined as being significantly expressed above genomic background (described above) in at least two of the triplicate samples for at least one blood cell type. This subset of enhancers was clustered for heat map visualization using complete linkage agglomerative hierarchical clustering based on enhancer usage per cell type (binary matrix) and Manhattan distance.
