Classes at binding sites and in the promoter regions. The position of each mosaic class has been plotted as in Figure 1A. The area of each circle shows the proportion of binding sites in the class for (a) all 17 transcription factors (b) the transcription factor ZNF263 (c) the transcription factor SRF. Subplot (d) gives a comparison for bases in promoter regions (defined as the 1000 bases upstream of the TSS — the plot is based on all coding genes). The preferred classes are shown in red and contain (a) 75%, (b) 86% and (c) 79% of the binding sites. In (d) the preferred classes contain 60% of the bases--this percentage is high but not as high as for (a). The lack of symmetry in Figures 2B and 2C implies a preferred orientation/strand of the binding site within the class.