CCL2 and severe acute respiratory syndrome: Similar to the lung pathology of severe acute respiratory syndrome (SARS), the lungs of patients with COVID-19 also exhibit pulmonary alveolar edema with hemorrhage, necrotizing bronchiolitis, alveolitis with inflammatory injury of epithelial cells, and other lung damage, accompanied by increased levels of IL-2, IL-7, IL-10, G-CSF, IP-10, MCP-1, MIP-1a and TNF-α, suggesting that there may be a cytokine storm related to the severity of the disease[8].