Fig. 1From: Useful biomarkers for assessing the adverse health effects of PCBs in allergic children: pediatric molecular epidemiologyDifferences in the expression level of IL-8 mRNA between non-asthmatic (control) and asthmatic children in three different sub-groups (tertiles) that exhibited low, medium, or high serum levels of PCB congener #163 + 164 [18]. P values were obtained using the Mann–Whitney U testBack to article page