We found that the VNTR polymorphism of IL-4 gene has significantly increased the risk of preeclampsia (RP2/RP1 versus RP1/RP1, OR, 2.8 [95% CI, 1.7 to 8.8]; P = 0.0001 and RP2/RP2 versus RP1/RP1; P = 0.002). Here, IL4 is linked to preeclampsia.