As a multifactorial and polygenic disease, COPD is caused by many factors, including smoking, advanced age, systemic inflammation, and especially pathways or processes influenced by protein–protein interactions (PPIs), such as oxidative stress and protease activity affected by interactions between glutathione S-transferase M1 and matrix metalloproteinases 1, 9, and 12 in the pathogenesis of COPD [2]. Here, MMP1 is linked to chronic obstructive pulmonary disease.