Boyuk et al., Li C. et al.: higher chemerin levels (serum and plasma) in COPD patients [59,60].Li C. et al.: association between plasma chemerin levels and disease severity (hospitalizations) [60].Galecka et al.: no significant difference in serum chemerin levels between COPD patients and controls [61]. Here, RARRES2 is linked to chronic obstructive pulmonary disease.