Several experiments showed that tumor necrosis factor (TNF)-α can induce IL-34 expression via NF-κB pathway, while IL-34 can act as a pro-inflammatory factor, inducing the secretion of other cytokines and chemokines including IL-6, IL-8, and CCL2 (Eda et al., 2010), and further aggravating the development of atherosclerosis plaque. This evidence concerns the gene CCL2 and atherosclerosis.