Differences in regulatory potential and allelic TF binding affinity for Lung.cancer and Breast.cancer LD80 SNPs. The plots present potentially affected TFBS, with the upper panel (A & C) displaying SNPs that confer stronger TFBS patterns in cancer patients with the minor allele while the lower panel (B & D) displayed an decrease in TF binding affinity. The x-axis represents the relative regulatory potential, defined as log2 ratio of regulatory potential index between cancer and normal cells plus 1. The relative regulatory potential is indicated as positive for higher regulatory potential in cancer cells (A549 for A and B; MCF-7 for C and D) and negative for higher regulatory potential in the corresponding normal cells (NHLF normal lung fibroblasts for A and B; HMEC breast normal cells for C and D). The y-axis shows the -1xlog2 transformation of empirical p-values for motif affinity score changes. The data shown on the plot are restricted to PWMs with p-values<0.05 from the two-tailed test, and for visualization purposes, only PWMs with scores > 85 in at least one allele are shown. TFs with an increase or decrease of TF binding affinity where the SNP has non-zero regulatory potential in either cancer or normal cells are labeled along with the corresponding SNP. SNPs with zero regulatory potential index in both cells are represented by gray dots, whereas those with regulatory potential indices >0 in both cells are colored in blue. SNPs with regulatory potential index restricted to a single cell type (cancer or normal cells) are colored in red and green, respectively. In plot C, a red arrow indicates a SNP rs1391720 that is discussed in the text. The vertical bar illustrates the degree of difference in TF affinity.