CXCL11 and influenza: In the BAL fluid of patients with COVID-19, significantly increased and extremely high levels of the cytokines IL-1β, IL-1RA, IL-17A, TNF-α, and G-CSF and the chemokines CCL7, CXCL1, CXCL8, CXCL11, and CXCL12α were found in comparison with BAL fluid of patients with influenza.