Furthermore, Shiels et al. conducted a nested case–control study where they demonstrated that the serum levels of some circulating inflammation markers, such as CXCL13 (C-X-C motif chemokine ligand 13), CRP (C-reactive protein), CCL22 (C-C motif chemokine 22) and IL-1RA (interleukin-1 receptor antagonist) were associated with increased lung cancer risk and offered a good separation in 10-year lung cancer cumulative risk between former smokers and current smokers [60]. This evidence concerns the gene CCL22 and lung cancer.