EDN1 and respiratory failure: The infection caused by SARS-CoV-2 and its progression to respiratory failure is driven by a strong and dysregulated immune-inflammatory response, which leads to elevated levels of pro-inflammatory cytokines including interleukin 6 (IL-6) and endothelin-1 (ET-1) in the body and a “cytokine storm” causing accumulation of neutrophils within the lungs, destroying alveolar capillaries.