CCL2 and COVID-19: In COVID-19, this cytokine storm is characterised by the increase of interleukin (IL)-2, IL-7, granulocyte-colony stimulating factor, IFN-γ, inducible protein (IP)-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP) 1-α, and tumour necrosis factor (TNF)-α [17].