Overlaps between promoter binding regions for ELK1, SRF, and GABPA. (A) Venn diagrams showing the overlap in target region binding between ELK1 FDR < 10, SRF FDR < 10, and GABPA ChIP-seq (Valouev et al. 2008) datasets. Comparisons were made with GABPA binding regions that overlap with the tiled regions on the Affymetrix promoter arrays. The total number of binding regions in each sector is shown, with percentages also provided relative to the total number of ELK1 targets. (B) Summary of the three classes of ELK1 target genes identified in this study, which are bound by (1) ELK1 and SRF, (2) ELK1 or GABPA, or (3) ELK1 alone. The # symbol indicates that redundancy with other ETS-domain proteins is likely.