CCL2 and COVID-19: Key inflammatory chemokines and cytokines such as interleukin (IL)-6, IL-8, tumor necrosis factor alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein 1 alpha (MIP-1α) are elevated in COVID-19 subjects, and this is typically more pronounced in patients with severe manifestations of the disease9,15,17,42.