ACE2 and obesity due to melanocortin 4 receptor deficiency: Furthermore, conditions linked to obesity, such as endothelial dysfunction and enhanced expression of angiotensin-converting enzyme 2 (ACE2), contribute to acute COVID-19 that confers vulnerability to post-acute sequelae of SARS-CoV-2 infection (Long COVID), an array of signs and symptoms with prolonged multisystem involvement that persist for more than four weeks after an infection has been diagnosed [11,12].