CCL2 and COVID-19: Moreover, plasma IL-2, IL-7, IL-10, GCSF (granulocyte colony-stimulating factor), IP-10 (interferon gamma-induced protein-10), MCP-1 (monocyte chemoattractant protein-1), MIP-1α (macrophage inflammatory protein-1 alpha) and TNF-α (tumor necrosis factor-alpha) are consistently higher in intensive care unit (ICU) patients compared to mild cases (Huang et al., 2020), suggesting that virus-induced exaggerated immune responses and the resulting immune injuries are involved in the progression of COVID-19.