Some tissues share eQTLs more than others. Fig. 6 summarizes eQTL sharing by magnitude between all pairs of tissues (see Supplementary Fig. 5 for sharing by sign). In addition to strong sharing among brain tissues, mash identified increased sharing among other biologically related groups, including arteries (tibial, coronary and aortal), two groups of gut tissues (one group containing esophagus and sigmoid colon, the other containing stomach, terminal ilium of the small intestine and transverse colon), skin (sun-exposed and non-exposed), adipose (subcutaneous and visceral-omentum) and heart (left ventricle and atrial appendage). Figure 6 also reveals heterogeneity in effect sizes in cerebellum versus non-cerebellum tissues, and highlights sharing between pituitary and brain tissues.
