We found 35 correlated DMC-DEG pairs and revealed several significant mediation relationships among them including TLR5, SLC9A3, SERPINE1 and GRK5. Other genes such as RMD4A, HNF1A and GAL3ST2 showed insignificant mediation, implying that the association between DNAm and asthma severity and lung function occur via other mechanisms in BECs. The gene discussed is SERPINE1; the disease is asthma.