This is corroborated by our data suggesting that lnc-IL7R induction may have a potential regulatory role in normal bronchial cells exposed to PM2.5 because endogenous lnc-IL7R expression was upregulated in normal but not COPD lung epithelial cells or PBMC, and lower lnc-IL7R expression was associated with emphysema in COPD (unpublished data). Here, IL7R is linked to chronic obstructive pulmonary disease.