Panels A and B: RvD1 was measured in bronchoalveolar lavage fluid (BAL) and serum from non-smokers without COPD and from COPD patients by EIA as previously reported (Croasdell, et al., 2015). Panel C: Levels of eicosanoid oxidoreductase (EOR), an enzyme that degrades and inactivates RvD1, were measured in lung tissue from non-smoking donors or COPD patients, as previously reported (Hsiao, et al., 2015).