FCN2 and newborn respiratory distress syndrome: Furthermore, ficolin-2 concentration could better differentiate between mild and moderate/severe RDS in newborns born at GA <33 [AUC=0.807, 95% CI (0.644-0.97), p=0.0002] with sensitivity of 75% and specificity of 91% at cut off 1469 ng/ml (Figure 3D).