Necroptosis, an important mode of lung epithelial cell death in COPD, causes the release of cell contents into the extracellular environment, including a large number of danger-associated molecular patterns (DAMPs), such as high-mobility group box-1 (HMGB1), S100 proteins, double-stranded DNA and ATP [30]. The gene discussed is HMGB1; the disease is chronic obstructive pulmonary disease.