On the other hand, virus infections trigger the production of inflammatory cytokines and chemokines in the respiratory tract including interleukin (IL)-6, chemokine (C-C motif) ligand 2 (CCL2), CCL5, CCL8, chemokine (C-X-C motif) ligand 8 (CXCL8), CXCL9, CXCL16, and CXCL2. The gene discussed is CCL2; the disease is viral infectious disease.