a, 3C assays showing the loss of chromatin loop between the SNP (highlight in yellow) and ACBD7 locus after displacing CTCF binding with either dCas9-KRAB or dCas9 protein. b,c, Bar plots showing the changes of allelic gene expression upon blocking CTCF loops with dCas9 or dCas9-KRAB. d–f, CTCF blocking experiments at GPNMB locus. n = 2 biologically independent experiments. All data are presented as means ± SEM from 4 replicated experiments. **P < 0.01, ***P < 0.001. NS, no significant difference. Two-sided Wilcoxon test. The height of browser tracks indicating the raw counts of ChIP-seq.