CCL4 and COVID-19: Increased levels of cytokines and chemokines have been detected in the blood of patients with COVID-19; such factors include interleukin 1 beta (IL-1β), IL-6, IL-17, IL-8, C-C motif chemokine ligand 2 (CCL2)/monocyte chemoattractant protein-1 (MCP1), CCL3/MIP1α, CCL4/macrophage inflammatory protein-1 beta (MIP1β), granulocyte-macrophage colony-stimulating factor (GM-CSF), platelet-derived growth factor beta (PDGFβ), TNF, and vascular endothelial growth factor (VEGF) (Nile et al., 2020).