Are super enhancers structurally insulated in chromatin loops?
Although there is evidence that chromatin neighbourhoods, formed by the zinc-finger protein CTCF, can sequester enhancers and their target genes, there is limited in vivo evidence for CTCF demarcating super-enhancers and preventing cross talk between distinct regulatory elements. CTCF sites are porous borders, allowing a super-enhancer to activate a secondary target.