CCL2 and chronic obstructive pulmonary disease: The comparison of COPD patients with the history of smoking to the control group indicated that in COPD/tobacco patients, the levels of cytokines, such as IL-1RA, IL-1α, IL-1β, IL-6, TNF-α, IL-17, IL − 8 MIP-1β and VEGF, were statistically higher compared to the control group, with p-values of 0.014; 0.006; 0.025; 0.033; 0.048, 0.041; 0.009, 0.012 and 0.035 respectively (Fig. 1), without statistically significant differences in the concentrations of cytokines, such as IP-10, MCP-1, GRO, sCD40L, G-CSF and GM-CSF (Fig. 1).