CCL3 and systemic inflammatory response syndrome: Patients with severe COVID-19 tend to have a high concentration of pro-inflammatory cytokines (IL-2, IL-7, IL-10, G-CSF, TNF-α, CXCL10, MCP1, and MIP1α) (3), suggesting that a cytokine release syndrome (CRS) (4) (also loosely referred to as a cytokine storm), which is a form of life-threatening systemic inflammatory response syndrome (SIRS), can often feature in severe COVID-19 infections.