We examined whether SNPs with lower p-values were more likely to localize to regions of potential regulatory significance in the genome (DHS or the H3K4me3 histone mark). When collapsing all cell types together, there was a clear trend toward general enrichment (Figure 4): as the p-value threshold becomes more stringent, variants were more likely to be located in DHS or H3K4me3 sites. When tissue types were examined separately, the most pronounced evidence of enrichment for DHS was in monocytes; for H3K4me3 histone marks, the strongest enrichment was in spinal cord cell lines derived from astrocytes. The second-highest degree of enrichment among nervous system-related tissue types was for DHS in cerebellar tissue. Complete results are available in Table S4.
