CCL2 and infection: In severe cases of COVID-19, multiple studies have indicated higher levels of IL-2, IL-6, IL-7, IL-10, CXCL10(IP-10), CCL2 (MCP-1), TNF-α, CCL3(MIP-1α), and G-CSF when compared to patients with mild and moderate infections [14,21,50,51,52,53].