CCL2 and COVID-19: Most COVID-19 patients with ARDS are characterized by markedly elevated cytokine levels including interleukin (IL)-2, IL-6, IL-7, granulocyte colony-stimulating factor (G-CSF), interferon-γ inducible protein 10 (CXCL10), monocyte chemoattractant protein 1 (CCL2), macrophage inflammatory protein 1-α (CCL3) and tumor necrosis factor-α (TNF-α) [32].