Marked elevation of cytokine levels such as interleukin (IL)-6, IL-7, IL-1, IL-10, IL-2, granulocyte colony-stimulating factor, C-X-C motif chemokine ligand 10, monocyte chemoattractant protein-1, macrophage inflammatory proteins-1 alpha, and tumor necrosis factor (TNF) in patients with severe COVID-19 is the characteristics of cytokine storm 8. Here, IL2 is linked to COVID-19.