While we concentrated on peripheral blood, we could replicate 35% of the trans-eQTLs in monocytes. Particularly surprising was the observation that for SNPs, known to affect the volume of platelets or erythrocytes the identified trans-eQTL effects in whole blood were also present in these monocytes. Among these replicated genes are a considerable number of highly plausible trans-genes. For example, for mean platelet volume SNP rs12485738 we detected the same trans-eQTL effects on seven well-known blood coagulation genes (F13A1, GP1BB, GP9, ITGA2B, MMRN1, THBS1 and VWF) in both the peripheral blood data and the monocyte data. Interestingly, in both datasets, trans-effects for this SNP on another 31 genes were identified as well, which suggests these genes play a role in blood coagulation. It can thus be concluded that trans-eQTLs, identified in peripheral blood, generally apply to monocytes as well. We assumed these eQTLs might therefore also be present in other, non-blood tissues, as previously observed for rodents [47]–[49]. Indeed we could replicate some of these trans-eQTLs in a smaller dataset of four non-blood tissues. Importantly, as mentioned before [46], the allelic
