Severe COVID-19 illness is associated with a cytokine profile similar to that seen in sHLH, including increased interferon-induced protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein (MIP) 1, IL-2, IL-6, IL-7, granulocyte colony-stimulating factor (G-CSF), and TNF-α [44,45]. This evidence concerns the gene CSF3 and COVID-19.