Since SNPs in strong LD with a SNP directly responsible for regulating gene expression levels are also correlated with gene expression levels, it is difficult to determine which SNP is the causative one. We assumed that the genetic regulatory locus would be included in the eQTL region, defined as the genomic range in which the SNPs in LD (r2>0.8) with the eQTL SNPs identified in our study are found. Although the numerous SNPs in LD with each other hindered the identification of the responsible SNP, the locations of the eQTL regions indicated that eQTLs are widely distributed both upstream and downstream of the gene, as well as within the gene.
