CCL2 and Alzheimer disease: Among the top 10 upregulated genes in macrophages in the AD group, chemokine- and inflammation-related genes, such as CCL2 (C-C Motif Chemokine Ligand 2) [26], CCL20 [27], S100A8 (S100 Calcium Binding Protein A8) [28], and S100A9 [29], and extracellular matrix and metalloproteinase-related genes, such as VCAN (Versican, the protein encoded is a major component of the extracellular matrix) and TIMP1 (TIMP Metallopeptidase Inhibitor 1), were highly expressed [30,31].