TNF and endothelial dysfunction: There are two suggested explanations for this either via the renin angiotensin system, or by causing endothelial dysfunction due to the production of high levels of pro-inflammatory agents such as angiotensin II, cytokines, interleukin-6 and tumor necrosis factor-α causing an imbalance between relaxing and constrictor factors, moreover, hypertension is one of the main risk factors for kidney dysfunction, if the blood pressure is not controlled, it can lead to acute kidney injury (AKI) in COVID patients (25, 26).