Due to the cross-national, ethnic, and sex differences in visceral fat distribution, autoimmune diseases, cytokine-related systemic inflammation, and ACE2 expression [30,48,59,69], the approach suggested in this article may help to explain differences in infection and mortality rates across countries, races, ethnicities, and sexes, as well as in defining the evolutionary role of visceral fat in the human body. The gene discussed is ACE2; the disease is autoimmune disease.