IL7 and acute respiratory distress syndrome: High expression of pro-inflammatory mediators, including interleukin (IL)-2, IL-6, IL-7, IL-17A, and tumour-necrosis factor-α (TNF-α) in patients with severe-to-critical COVID-19 pneumonia is the major cause of triggering cytokine storm which may result in acute respiratory distress syndrome (ARDS) leading to respiratory failure [8,11,14,15].