ACE2 and obesity due to melanocortin 4 receptor deficiency: Additionally, although it is possible to include other influences of COVID‐19 disease, such as age and obesity, in the MCT‐treated rat model, the model is still of restricted genetic diversity compared to humans, where sequence variations in ACE2,95 expression of TLR3 or TLR4,96 or preexisting type I IFN autoantibodies97 can impact COVID‐19 severity in humans.