CD40LG and pulmonary emphysema: Positive correlations were also found between lower prevalence of emphysema and levels of biomarkers of T cell activation (CD40 ligand), metabolism (M2-PK and 6-phosphogluconate dehydrogenase) and proteostasis (eg. Ubiquitin+1, SUMO3, UBC9, Sorting nexin 4, SNAA, UFM1) markers (S4 Table in S1 File).