Scientists have created pluripotent stem cells in which the extrusion of cohesin loops can be induced to be disrupted without side effects of the cell cycle.[2][1] Transcriptional dysregulation is cell type specific and not all loci with distal enhancers are equally dependent on cohesin extrusion.[2] Using comparative genome editing, they showed that enhancer-promoter communication across only 20 kilobases requires cohesin.[2] However, promoter-proximal elements support long-range cohesin-independent enhancer action, even through strong CTCF insulators.[2] Transcriptional dynamics and the emergence of embryonic cell types remain largely robust despite impaired extrusion.[2] The study provides mechanistic insight into specificity by cell type and genomic context in enhancer biology.[2]