NFIL3 and chronic obstructive pulmonary disease: In this study, we simulated the lung microenvironment of COPD patients using single-cell sequencing data from COPD mice and tobacco-induced COPD mouse models, examined the expression patterns of Tim3 and NFIL3 in the lungs, and investigated the effects of the NFIL3/Tim3 axis on Th1 differentiation in COPD mice.