IL17A and preeclampsia: It was found that in preeclampsia, a decrease in Treg in maternal peripheral blood and tissue was accompanied by an increase in pro-inflammatory Th17, CD8+ effector cells and trophoblast apoptosis (33).Th17 Induced cytolytic NK cells’ function, placenta perforin production, IL-17, IL-6, IFN-γ, and TNF-α cytokines.