To understand whether serum MBD3 expression has diagnostic values on CPP, we draw a ROC curve to distinguish CPP patients from healthy subjects with the expression level of MBD3, which illustrated the area under the curve (AUC) as 0.9309 and cut-off value as 1.475 (92.66% sensitivity and 86.49% specificity) (P < 0.0001, Figure 1b). The gene discussed is MBD3; the disease is central precocious puberty.