The positive predictive value (PPV) and negative predictive value (NPV) are both higher in the model with CST1 (0.8235 and 0.9062, respectively) compared to the model without CST1 (0.6471 and 0.7188), meaning the model with CST1 is more reliable when predicting both AD patients and healthy controls. Here, CST1 is linked to Alzheimer disease.