Fig. 2

Analyses of M2 polarized alveolar macrophages (CD206⁺) in the study cohort. The percentage of M2 (CD206⁺) alveolar macrophages was low in donors, and increased with smoking and COPD severity. Two ventilated subjects in the donors group are identified (circles). Bottom and top of each box plot, 25^th and 75^th percentiles; solid line, median; brackets, 10^th and 90^th percentiles