IL9 and COVID-19: According to Huang et al. (2020), levels of IL-1β, IL-1RA, IL-6, IL-7, IL-8, IL-9, IL-10, macrophage colony-stimulating factor (M-CSF), IFN-γ, platelet-derived growth factor (PDGF), TNF-α and vascular endothelial growth factor (VEGF) in COVID-19 patients were much higher as compared to healthy individuals, indicating that cytokine storm is being associated with the occurrence of extrapulmonary multiple organ dysfunction during the progression of COVID-19 (Effenberger et al., 2020; Ojetti et al., 2020).