TLR7 and COVID-19: Stimulation with the TLR7 agonist imiquimod (IMQ) of primary peripheral blood mononuclear cells (PBMC) from the patients resulted in a transcriptionally impaired host type I IFN response downstream of the TLR7 pathway, as evidenced by the impaired upregulation of IRF7, IFNβ1 and interferon-stimulated gene ISG15, and by an abrogated production of IFNγ, supporting the importance of intact TLR7 signaling in COVID-19 pathogenesis.