IL2 and COVID-19: Out of the 17 cytokines tested, nine (IL-1β, IL-2, IL-4, IL-5, IL-12, IL-13, IL-17, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF)) were undetectable in the peripheral blood of COVID-19 patients.