TMPRSS2 and COVID-19: Although intrauterine transmission has been documented, it appears to be rare, which is hypothesized to be related to the low levels of SARS-CoV-2 viremia and the decreased co-expression of ACE2 (angiotensin-converting enzyme 2) and TMPRSS2 (transmembrane serine protease 2), which are needed for coronavirus entry into cells in the placenta [66].