TNF and endothelial dysfunction: It is now widely recognized that placental ischemia promotes the release of pro-inflammatory cytokines such as TNF-α, IFN-γ and certain interleukins (e.g., IL-2, IL-6, etc.)from the placenta into the maternal circulation, and these cytokines then lead to increased expression of adhesion molecules and endothelial dysfunction in the maternal vascular system, which is positively associated with increased blood pressure, and this contributes to the pathogenesis of preeclampsia (41).