IL6 and COVID-19: Notably, higher plasma levels of pro-inflammatory cytokines or chemokines, such as IL-6, -2, -7, -10, colony stimulating factor (CSF)3 (G-CSF), C-X-C motif chemokine ligand 10 (CXCL10/IP10), C-C motif chemokine ligand 2 (CCL2/MCP1), CCL3 (MIP1A), and TNF and reduced peripheral blood frequencies of lymphocytes, especially T lymphocytes, were found in patients with severe COVID-19 compared to individuals with non-severe disease(54, 57, 59).