PIGF and preeclampsia: Increased concentrations of sFlt-1 lead to PIGF and VEGF being sequestered (35, 52); hence, an imbalance in the expression of angiogenic and antiangiogenic factors leads to inadequate angiogenesis and disruption of the maternal endothelium and immunological balance advancing to the clinical signs of preeclampsia (Figure 1) (9, 17, 52).