FURIN and obesity due to melanocortin 4 receptor deficiency: Several mechanisms have been proposed for the increased risk of COVID-19 in patients with diabetes, including an elevated level of ACE-2 receptors and furin, and dysregulated immune response, while the following factors contribute for the obesity to be associated with the worse prognosis of COVID-19: the compromised ventilation at the base of the lung and immune response (38).