1% macrophage-specific (4× PU.1 tag difference) (Figure S2D). C/EBP and Oct-2 binding sites exhibited similar relationships with gene expression as observed for PU.1 (Figure S2E). C/EBP- and Oct-2-bound regions were highly enriched for C/EBP and octamer motifs, respectively (Figure 2E). In addition, C/EBP-bound regions were co-enriched for a recently described C/EBP:AP-1 composite element (Cai et al., 2008) as well as canonical PU.1 and AP-1 motifs, whereas Oct-2-bound regions in B cells were highly enriched for a PU.1 as well as a PU.1 -IRF composite motif (Figure 2E).
