IL7 and COVID-19: Principle behind use: severe cases of COVID-19 are characterized by a cytokine storm defined as a sudden production of cytokines, such as IL-2, IL-7, IL-10, granulocyte colony-stimulating factor (G-CSF), MCP1, MIP-1a, and TNF-α, secondary to the upregulation of the inflammatory process in COVID-19 [21].