CCL2 and COVID-19: Some studies showed that elevated levels of IL-6, TNF-α, MCP‐1, MIP-1α, and G‐CSF were correlated with severe COVID-19.39–41 Pro-inflammation cytokines such as IL-1β, IL-6, and TNF-α, bind to their receptors, further mediate inflammation through triggering intracellular signaling pathways, including the nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase, and Janus kinase-signal transducer and activator of transcription pathways.