ERN1 and Alzheimer disease: We, therefore, hypothesized that rs56201815 is a cis-eQTL of ERN1 in the brain, and the detrimental effect of rs56201815 on AD is mediated by upregulating the expression of ERN1. To test this hypothesis, we examined the effect of rs56201815 on the expression of ERN1 using RNA-seq data in ROSMAP and GTEx, and microarray data in ADNI.