This was associated with a higher rate of proinflammatory cytokine synthesis in visceral adipocytes compared to subcutaneous adipose tissue, which together may be one of the links between diabetes, obesity, and COVID-19 severity, as visceral adipose adipocytes express higher levels of ACE2 and are more susceptible to SARS-CoV-2 infection [146]. This evidence concerns the gene ACE2 and diabetes mellitus.