ACE2 and infection: The evidence that exists relating to the expression of ACE2 and TMPRSS2 in stem cells indicates that stem cells from bone marrow and amniotic fluid have very little expression, and—in the case of adipose tissue stem cells—the expression decreases less than 10% without finding important changes in its expression when faced with inflammatory events [42], which indicates a low risk of infection of these cells to SARS-CoV-2.