We have made extensive use of publicly accessible data with the aim of better understanding 1 facet of SLC1A1 functionality—gene expression. Some of the most extensive gene expression data sets currently available were obtained from lymphoblastoid cell lines, and we used these data to better understand how genetic SLC1A1 variation might affect its gene expression levels. To this end, it was first necessary to determine whether or not SLC1A1 is expressed in lymphoblastoid cell lines at sufficiently high levels for quantitative analyses and then to identify the degree to which (if at all) SLC1A1 gene expression in lymphoblastoid cell lines constitutes a heritable trait. The additive heritability (h2) value of 0.23 determined herein, while highly significant, is quite modest compared with some other genes expressed in lymphoblastoid cell lines, whose heritabilities ranged between 0.18 and 1, with a median of 0.34.45 In light of the relatively modest additive heritability for SLC1A1 expression now determined in our analysis, it is not surprising that the eQTL markers identified herein also had a small effect size (Figure 1). Nevertheless, our approach proved valuable,
