IL4 and COVID-19: Various studies have reported abnormal serum levels of the following cytokines in COVID-19 intensive care unit (ICU) patients: IL-1, IL-2, IL-4, IL-6, IL-7, IL-10, IL-12, IL-13, IL-17, macrophage colony-stimulating factor (M-CSF), G-CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF), IFN-γ, hepatocyte growth factor (HGF), TNF-α, and vascular endothelial growth factor (VEGF) [8,9,10,11].