HIF1A and COVID-19: In severe cases of COVID-19, HIF-1α activation can lead to cytokine storm by activation and stabilization of immune cells including macrophages and neutrophils causing the production of high amounts of inflammatory cytokines by these cells, vascular leakage (by up-regulation of the VEGF) and destruction of the alveolar-interstitial-endothelial epithelial complex barriers (Fig. 2).