CCL4 and COVID-19: Specifically, there was a significant overexpression of IP-10, TNF-α, IFN-α2, IFN-γ, IL-1RA, MCP-3, M-CSF, IL-7, MCP-1, MIP-1β, IL-15, IL-12 (p40), PDGF AA, IL-6, FLT 3L, and IL-10 in COVID-19 patients, as shown in Fig. 1.