PLA2G7 and chronic obstructive pulmonary disease: Also, the expression levels of PLA2G7 in never-smokers and normal smokers were significantly lower than that of patients with COPD (including 22 patients with COPD, 24 never-smokers, and 42 smokers from GSE130928; and 12 patients with COPD, 24 never-smokers, and 34 smokers from GSE13896).