ROC analysis showed that the AUC (95%CI) = 0.7723 (0.6879-0.8567) of BDNF in predicting prognosis of COPD patients, indicating the value of BDNF in this regard, but the mechanism is not clear and may be related to depression of patients, so further exploration and research are needed. The gene discussed is BDNF; the disease is chronic obstructive pulmonary disease.