coding variants [1], [2], little is known about the degree of population differentiation of regulatory variants, either for those with regulatory effects on nearby genes (cis-eQTLs) or those acting over longer genomic distances (trans-eQTLs). This deficit of knowledge needs to be addressed given that it is likely that: (i) a large number of high-frequency eQTLs exist in human populations; (ii) cis-regulatory variation contributes to both population-selective effects [3], [4] and common disease signals [5], [6], [7]; (iii) a large fraction of species' differentiation is driven by regulatory changes [8], [9], [10].
