The team identified the connections between rs9349379 and EDN1 by deleting a region of DNA at the SNP in human pluripotent stem cells and then converting these immature cells into endothelial cells and vascular smooth muscle cells. (broadinstitute.org)
Importantly, deleting these regions affected the response of vitamin D activation to hormones, but not to inflammation - related molecules, indicating that these regions were key to allowing researchers to separately study the two types of calcitriol production. (sciencedaily.com)
Maybe the deleted region contained imprinted genes, and thus had different effects depending on how the genes were expressed. (sciencemag.org)