IL6 and cystic fibrosis: Elevated interleukin-6 (IL-6) levels were linked with severe COVID-19 disease course and mortality.34,35 Nevertheless, the airway epithelia in CF patients had reduced IL-6 levels suggesting a protective effect against severe SARS-CoV-2 infection.34 Marcinkiewicz et al. reported high interleukin-8 (IL-8) levels and extremely low IL-6 and interleukin-10 (IL-10) levels in the sputum samples of 39 patients with advanced CF and chronic Pseudomonas aeruginosa infection.