IL2 and COVID-19: Very high levels of IL-2, IL-7, IL-10, tumor necrosis factor (TNF)-α, and granulocyte colony-stimulating factor (G-CSF) were observed in coronavirus disease 2019 (COVID-19) patients requiring intensive care.121 These syndromes are major contributors to the severity and mortality of COVID-19.122–125 Most of these cytokines signal through the JAK-STAT pathway.