GDF2 and acute respiratory distress syndrome: Next, we questioned whether NE in plasma could contribute to BMP9 cleavage, as primed circulating neutrophils (with increased capacity for systemic degranulation) were identified in patients with ARDS (32), activated neutrophils release a number of proteases on degranulation (29), and significantly higher concentrations of NE were found in plasma from endotoxemic mice (Figure 4F).