Although circulating IL-18 and IL-12p40 levels were also elevated yielding similar IL-18/IL-12p70 and IL-12p70/IL-12p40 ratios as in normal pregnancy, the relative abundance of circulating IL-2 and IFN-γ over IL-4 - as shown by the increased serum IL-2/IL-4 and IFN-γ/IL-4 ratios - might provide a Th1-biased systemic environment in preeclampsia. Here, IL4 is linked to preeclampsia.