The specificity or sharing of eQTLs among different tissues and cell types is of considerable biological interest (8, 22, 24), yielding insights into differential genetic regulation among tissues. Furthermore, cross-referencing tissue-specific eQTLs with disease genetic associations could help identify tissues most relevant to disease biology. We used the GTEx pilot data to examine eQTL sharing across multiple tissues and leveraged the large tissue range to discover weak but constitutively active eQTLs.
