By contrast, other cytokines, including IL-1β, IL-1RA, IL-7, IL-8, IL-9, IL-10, basic fibroblast growth factors (FGF), GCS-F, GM-CSF, IFN-γ, CXCL10, CCL2, CCL3, CCL4, platelet-derived growth factor subunit B (PDGFB), TNF-α, and vascular endothelial growth factor-A (VEGF-A), showed higher expression in both ICU and non-ICU patients with COVID-19 (33, 36, 37). Here, CCL4 is linked to COVID-19.