Here, we detected that DNAJB1 was overexpressed in the CS‐induced emphysema mice model, which was consistent with the high DNAJB1 level in COPD patients indicated by Sun et al.17Functional experiments showed that DNAJB1 overexpression aggravated PMVECs apoptosis induced by CSE and could overturn miR‐23a‐3p‐mediated the inhibition on CSE‐induced PMVECs apoptosis. This evidence concerns the gene DNAJB1 and pulmonary emphysema.