A SNP (rs4065275) in an enhancer within the 1st intron of ORMDL3 promotes CTCF binding, whereas another SNP (rs12936231) downstream of the enhancer impairs CTCF binding. SNPs therefore alters three-dimentional organization in the asthma-risk allele to facilitate the expression of ORMDL3, which inhibits IL-2 production. Here, CTCF is linked to asthma.