on those genetic variants known to influence gene expression (so-called expression quantitative trait loci, or eQTLs), rather than examine all SNPs. Massive publicly available datasets now provide comprehensive maps of enhancers, insulators, promoters, and eQTLs, all part of the genetic regulatory system that controls gene expression levels. Chromatin state information can be used to prioritize SNPs with genomic function (Pickrell, 2014). Whole-genome sequences are especially valuable for these tests, as they provide exhaustive directly genotyped variants within functional regions instead of relying on tag SNPs and common variants. In fact, we are currently pursuing such analyses ourselves. When a significantly associated variant is eventually found and replicated, these functional categories can prove valuable in understanding how that variant influences the genome to affect the trait of interest.
