CCL2 and COVID-19: Several clinical studies on COVID-19 patients reported significantly elevated inflammatory biomarkers in circulation, including interleukin (IL)-2, IL-6, IL-7, monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1-α (MIP-1α), tumour necrosis factor-α (TNF-α), interferon-γ inducible protein (IP)-10, CRP, ferritin, and procalcitonin [7,27].