CCL2 and COVID-19: Hospitalized patients with severe COVID-19 show high levels of IL-2, IL-7, IL-10, G-CSF, TNF, CXCL10, MCP1, and MIP1α in serum [6], suggesting that severe COVID-19 is dictated as a cytokine release syndrome (CRS), which is a disorder induced by cytokine storms [12–14].