PGF and preeclampsia: These data underscore the recent observation that an imbalance in circulating factors with pro- and anti-angiogenic/vasculogenic functions, such as soluble vascular endothelial growth factor receptor 1 (VEGFR1, sFlt-1), placental growth factor (PlGF), and transforming growth factor co-receptor endoglin, is important in the pathogenesis of preeclampsia [41-44].