As a control region, we selected a well-known invariant CTCF binding site ∼50 kb proximal to ORMDL3 (near the GSDMA gene), which did not harbour any motif-disrupting asthma-risk SNP; this region did not show any significant change in CTCF binding (Supplementary Fig. 4a). This evidence concerns the gene CTCF and asthma.