We also compared the ratio of nuclear AhR protein to total AhR protein in placental tissues between the two groups, and the ratio was significantly lower in the preeclampsia group (control vs. preeclampsia: 0.680 ± 0.085 vs. 0.251 ± 0.034, t = 4.681, P = 0.003; Figure 1c). This evidence concerns the gene AHR and preeclampsia.