CCL2 and COVID-19: Most patients with severe COVID-19 have significantly elevated serum levels of pro-inflammatory cytokines, including interleukin (IL)-6 and IL-1β, as well as IL-2, IL-8, IL-17, granulocytes growth factors, interferon-γ-inducible protein 10 (IP10), monocyte chemoattractant protein-1 (MCP1), macrophage inflammatory protein 1 alpha (MIP1α), and tumor necrosis factor alpha (TNFα).