In the comparison of the expression of IL-33 in the disease status of COPD, there was no increase in the expression of IL-33 in HBECs from COPD patients compared to HBECs from healthy subjects, which is inconsistent with a result previously reported that higher expression of IL-33 appeared in the airway epithelial cells from patients with COPD [10]. The gene discussed is IL33; the disease is chronic obstructive pulmonary disease.