IL6 and respiratory failure: Many cytokines are released in SARS-CoV-2 patients and cause a cytokine storm such as IL-6, IL-1, IL-2, IL-10, TNF-α, and IFN-, Increased level of IL-6 in the serum leads ARDS and adverse clinical outcome, such as respiratory failure (Tan K.S. et al., 2020; Tan L. et al., 2020).