ACE2 and COVID-19: Recently, some of us reported that two ACE2 single nucleotide polymorphisms (SNPs), known to be associated with higher ACE2 expression and lower COVID-19 susceptibility (44), are over-represented in our cohort of highly exposed seronegative HCW potentially explaining the higher sACE2 expression that we found in our work and the reduced risk of contracting SARS-CoV-2 infection (45).