claim: expression of sars-cov-2 receptor ace2 and the protease tmprss2 suggests susceptibility of the human embryo in the first trimester
evidence_1: expression of ace2 and tmprss2 in the pre-gastrulation human embryo.", "here, we examine human pre-gastrulation embryos to determine the expression patterns of the genes ace2 , encoding the sars-cov-2 receptor, and tmprss2 , encoding a protease that cleaves both the viral spike protein and the ace2 receptor to facilitate infection.", "with these considerations in mind, we address here when in human development is the earliest stage at which sars-cov-2 receptor, angiotensin-converting enzyme 2 (ace2), is first expressed and therefore when the human embryo could possibly become infected.", 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  "2020the sars-cov-2 receptor ace2 expression of maternal-fetal interface and fetal organs by single-cell transcriptome study.")