Thus, MK may enhance the signal transduction of the Notch2 signaling pathway through upregulation of the expression of the Notch2 receptor, the transmembrane protein NTM and downstream target HES1, and thereby regulate the cell cycle of AMSCs, promote ASMC proliferation, inhibit apoptosis, and lead to airway narrowing, thereby play a role in the development of COPD. The gene discussed is NOTCH2; the disease is chronic obstructive pulmonary disease.