PCSK9 and familial hypercholesterolemia: The area under the receiver operating characteristic (ROC) curve (AUC) for the prediction of hypercholesterolemia in NS patients using plasma PCSK9 was 0.71 (95% CI 0.58–0.84, p = 0.007) (Figure 4(a)), the Youden index was 0.42, and the corresponding PCSK9 value was 267.60 ng/ml.