Serum RKIP correctly classified LC patients from healthy subjects with 94% sensitivity and 91% specificity (AUC 0.94, accuracy 93%) by using a cut-off value of 3.86 μg/mL (Figure 2D), while it reached 72% sensitivity and 76% specificity (AUC 0.72, accuracy 74%) when the classification model was applied to LC patients vs. HR-HSs (cut-off value: 27 μg/mL). The gene discussed is PEBP1; the disease is laryngotracheoesophageal cleft.