NOTCH3 and idiopathic pulmonary arterial hypertension: The diagnostic cutoff of 13.0 ng ml−1 for serum NOTCH3-ECD was applied to the treatment-naive IPAH individuals and demonstrated an AUC of 0.95 (95% CI, 0.93–0.98) with sensitivity 88%, specificity 92%, precision 1.0, recall 0.84 and F1 score 0.91 (Fig. 5a).