In addition to using gene expression data, we further characterize our proliferation signature using ChIP-seq data for E2F1 transcription factor (TF) [9]. In the original paper, an extended set of genes identified through cluster analysis was linked to regulatory domain of E2F transcription factors by examining the overlap with E2F targets established in ChIP-chip [10] and global expression profiling [11] experiments, and computationally predicted E2F targets. Here, we used Genomics Portals to examine the newer ChIP-seq dataset assessing DNA binding of 15 different transcription factors, including E2F1, in mouse embryonic stem cells. Following steps can be conducted to obtain the respective heatmaps.