Advances in high-throughput genotyping and gene expression platforms have enabled genome-wide analysis of gene expression quantitative trait loci (eQTLs), allowing investigation of both cis and trans effects. Previous eQTL studies have examined the association between genetic variants and gene expression levels in various biological samples, including human whole blood [1], [2], lymphocytes [3], the liver [4], and, primarily, in lymphoblastoid cell lines [5], [6]. Recently developed web tools such as SNPexp [7] and Genevar [8] have enabled analysis of the correlation between SNP genotypes in HapMap genotype data and genome-wide expression levels in lymphoblastoid cell lines. Development of such tools in other cell types is also anticipated, as a substantial fraction of eQTLs are cell type-specific [9], [10], [11], [12].
