PGF and endothelial dysfunction: While markers of placental and endothelial dysfunction—such as increases in soluble FMS-like tyrosine kinase 1 (sFLT-1) levels, and decreases in vascular endothelial growth factor (VEGF) and placental growth factor (PLGF) levels—can be valuable clinically in ruling out suspected preeclampsia (5), early diagnosis of preeclampsia remains clinically challenging.