IL2 and COVID-19: Most patients with severe COVID-19 exhibited large amounts of pro-inflammatory cytokines and chemokines, such as IL-2, IL-6, IL-7, TNF-α, granulocyte colony stimulating factor (GCSF), CXC-chemokine ligand 10 (CXCL10), CC-chemokine ligand 2 (CCL2), and CCL3 (Chen N. et al., 2020; Huang et al., 2020).