...promoter and 103 enhancer regions (Wang et al., 2008; Creyghton et al., 2010). In contrast, H3K27me3 is a 104 repressive mark associated with polycomb-mediated transcriptional repression and gene 105 silencing (Bernstein et al., 2006; Barski et al., 2007), typically associated with regulatory 106 regions...