In COVID-19, CS is characterized by a particular set of cytokines highly increased in the serum of the patients, such as IL-2, IL-7, granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), Interferon gamma-induced protein 10 (IP10), macrophage inflammatory protein 1-α (MIP1-α), monocyte chemoattractant protein 1 (MCP-1), Tumour necrosis factor α (TNFα) and Interferon γ (IFN-γ). This evidence concerns the gene CCL2 and COVID-19.