Combined enrichment of association signal around the gene for seven diseases genotyped by the WTCCC after removal of the MHC region. The percentage of SNPs with p < α (red circles) is plotted for their distance to the closest gene. Values have been smoothed using a 50 kb sliding window (blue line). The light blue area represents the distribution expected by chance (95% confidence intervals) based on 100,000 permutations of the case/control status. The MHC region was defined as chromosome 6, position 25,930,839 to 33,297,046. The purple triangle represents the proportion of SNPs with p < α in coding exons.