wide range of cell types, including strong enrichment seen for H3K4Me3 (an activating modification found near promoters) marks in umbilical vein endothelial cells (HUVEC) (Supplementary Fig. 11). To explore expression at the level of cardiovascular cell types specifically, we use Fantom5 reference transcript expression data (see Online Methods) to cluster the 212 genes annotated to our 107 validated loci according to tissue specificity (Supplementary Fig. 12), with the significantly clustered genes forming four tissue-specific clusters, including a vascular smooth muscle cell (VSMC) and fibroblast cluster, an endothelial cell cluster (including probable endothelial cells in highly vascularized tissues), and a combined vascular cell cluster.
