Expression levels of the receptor of MCP-1, C-C motif receptor 2 (CCR2); the receptor for IP-10, chemokine (C-X-C motif) receptor 3 (CXCR3); and the receptor for IL-8, CXCR2 were assessed in the PBMCs from severe or mild COVID-19 patients compared to those from healthy controls. The gene discussed is CXCL8; the disease is COVID-19.