CCL2 and COVID-19: Certain factors such as high levels of markers of immune activation such as IL-4, IL-10, and TNF-α, or cytokine release syndrome (CRS) in patients with COVID-19 and high levels of granulocyte colony-stimulating factor (G-CSF), IL-6, IL-7, IL-8, IL-10, IL-1Rα, IFN-γ, TNF-α, granulocyte–macrophage (GM)-CSF, and monocyte chemoattractant protein-1 (MCP-1) are of great importance in this malignancy.