Finally, ROC analysis showed that both serum APN and Hb levels had a better predictive function for predicting vascular cognitive impairment in patients with ischemic stroke, but that the AUC for serum Hb was larger than that for serum APN, indicating that serum Hb levels are a better predictive indicator than serum APN levels. The gene discussed is GSTM1; the disease is ischemic stroke.