GDF2 and Down syndrome: At high sENG concentrations such as in PE patients, especially those with HELLP (Hemolysis, Elevated Liver enzymes and Low Platelets) syndrome, elevated sENG might be able to inhibit BMP9 (and BMP10) signaling in cells with low ENG and low ALK1 expression, especially when acting together with another confounding factor such as the elevated levels of sFLT1.