and enhancers) and PolyComb repressed regions, which matches prior findings that a large portion of mQTL SNPs resides in chromatin regions that are developmentally regulated22. Also, suppressed gene expression in PolyComb repressed regions might partly explain why eQTL and haQTL SNPs derived from adult samples are scarce in these regions. Notably, xQTL SNPs that are shared across all three molecular phenotypes are mainly enriched close to the TSS as well as in the 5′ and 3′ transcribed regions. With respect to transcribed sequences, we saw enrichment for all types of xQTLs in exons relative to introns (Figure 3B), with this trend being most striking for mQTLs.
