CP and Patent ductus arteriosus: In the Liverpool-UL cohort, significant ROC curves were obtained from Ctl-PDA data (AUC, 0.837; cut-off 22.83 ng/ml, with 75% sensitivity and 85.7% specificity) and from CP-PDA data (AUC, 0.669; cut-off 22.4 ng/ml, with 75% sensitivity and 63% specificity) (Figure 3A and Supplementary Table 6).