Patients with severe COVID-19 typically have increased serum levels of IL-6, IL-8/CXCL8, CXCL9, CXCL10, TNF-α, MCP1/CCL2, RANTES/CCL5, IL-18, and MIP-1α/CCL3, which promote a sustained pro-inflammatory state that may persist for up to 60 days [22, 23]. Here, IL6 is linked to COVID-19.