CCL4 and COVID-19: The disease is also associated with the elevated blood levels of other chemokines such as CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CXCL9/MIG, CXCL10/IP-10 and CX3CL1/Fractalkine, which shows that CXCL1 is only one of many COVID-19 factors.