CCL2 and COVID-19: Patients with severe COVID-19 show increased IL-2, IL-6, IL-7, granulocyte colony-stimulating factor (G-CSF), interferon-γ-inducible protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1-α (MIP-1), and tumor necrosis factor-alpha (TNFα) [35].