It is now well accepted that COPD is an inflammatory disorder characterized by both airway and systemic inflammation and that the inflammatory process intensifies with progression of disease.1–2 This new paradigm coupled with the recent proteomics revolution in technology has led to the search for proteins involved in the inflammatory pathways that could serve as biomarkers and/or targets of novel discoveries. Over the past decade, owing to the ease of procurement, standardization in measurement techniques and ready access to large biobanks of frozen serum or plasma (collected for reasons other than COPD), there has been a big boom in systemic inflammation-related research in COPD. A quick PUBMED search using key words “systemic inflammation” and “COPD,” for example, yields approximately 250 citations, the vast majority of which have been published since 2005 (Fig 1
). The designs of these studies are eclectic, ranging from case-control studies to randomized controlled trials evaluating a wide variety of different inflammatory biomarkers using mostly (but not exclusively) immunoassays.