IL9 and acute respiratory distress syndrome: Acute respiratory distress syndrome (ARDS) in patients with COVID-19 is associated with a severe inflammatory response (also referred to as a “cytokine storm”), which is associated with elevated serum levels of multiple inflammatory cytokines and chemokines (eg, interleukin-1 beta [IL-1β], IL-6, IL-7, IL-8, IL-9, IL-10, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, interferon-gamma [IFN-γ], IFN-γ-induced protein 10 kDa, monocyte chemoattractant protein-1 [MCP-1], and macrophage inflammatory protein-1 alpha [MIP-1α]).3