Figure 3. Differential allelic expression in ERCC1, IREB2, and PSMA4 supports the existence of cis-acting genetic regulations.

Allelic ratios (minor/common allele) for marker SNPs in cDNA (black bars) and genomic DNA (gray bars) from patients heterozygous for (A) rs11615 in ERCC1 gene, (B) rs12899351 in IREB2 gene, and (C) rs8053 in PSMA4 gene. Marker SNPs map in gene transcribed regions and, thus, can be genotyped in both cDNA and genomic DNA. Data are means and SE. Patients are subgrouped according to their genotypes at the eQTL SNPs for each gene. In particular, the heterozygous¹ subgroup consisted of cases that were heterozygous at all eQTL SNPs, while the homozygous² subgroup had cases that were homozygous for the common allele at all eQTL SNPs, and the third subgroup, homozygous³, formed for IREB2 gene only, consisted of cases that were homozygous for the common allele at three eQTL SNPs (rs2568494, rs16969968, and rs11634351) and homozygous for the minor allele at the fourth eQTL SNP (rs6495309) (see Fig. 2). **P < 0.001; ***P < 0.0001 (Wilcoxon’s signed rank test on paired log₁₀-transformed allelic ratios).