ACE2 expression is also found in extra-pulmonary tissues, one of greater importance being the small intestine surface where there is also high expression of this enzyme that helps as a co-receptor for nutrients, particularly amino acids (64), so one of the first hypotheses about the onset of the COVID-19 pandemic is intake of food from the Wuhan market with entry of the virus through the enteral epithelium with possible initial fecal-oral transmission. This evidence concerns the gene ACE2 and COVID-19.