PGAM5 expression in the alveolar macrophages was also higher in background lung from the 13 smokers with emphysema (H score, 95 ± 3.7, mean and SEM) compared to all patients without emphysema (smokers and non-smokers; 65 ± 13, p < 0.05). Here, PGAM5 is linked to pulmonary emphysema.