Our study represents the most genetically diverse eQTL study undertaken in humans to date, and has revealed extensive cis-regulation of gene expression in a single cell type. Taken together, our results suggest extensive cis- regulatory variation in humans, much of which will be uncovered as additional cell types are analyzed under a variety different cellular and developmental conditions, in larger numbers of individuals representing an even wider representation of human genetic diversity. Already these analyses contribute to the functional annotation of the human genome, and as a resource we have provided a list of variants that are associated with complex traits and are also the most significant SNP for an eQTL in this cell type. Given the genome-wide scale of these data and the diversity of populations surveyed, these eQTLs may assist in fine-mapping causal variants for complex traits and provide testable hypotheses for the mechanism underlying significant GWAS associations. Finally, our results reveal substantial diversity in frequency of regulatory variants among populations, with future work to understand how that spectrum has been shaped by selective and demographic processes, and how these functional variants contribute to higher order phenotypes, including those of health and disease.
