Figure 2From: Disturbance of the OPG/RANK/RANKL pathway and systemic inflammation in COPD patients with emphysema and osteoporosisComparison of serum IL-1β, IL-6, TNF-α levels among three groups. *p < 0.05. Abbreviations: IL: interleukin, TNF-α: tumor necrosis factor α.Back to article page