CCL2 and chronic obstructive pulmonary disease: Consistent with this, we detected significantly (p < 0.001) higher levels of IL-6 and IL-37 under basal conditions in the COPD cultures, as well as following infection with influenza H1N1 or even when treated with the pro-inflammatory viral double-stranded RNA analog poly(I:C) (Figure 2B), whereas no significant differences were observed for IL-8, RANTES, or MCP-1 (Figure S1).