TMPRSS2 and viral infectious disease: Although some studies have reported that SARS-CoV-2 RNA is undetectable in ovarian tissue, follicular fluid, cumulus cells, endometrial tissue, or vaginal fluid samples4–6, the potential for viral infection of oocytes remains a concern owing to the expression of the SARS-CoV-2 entry receptors, angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) in mature oocytes7.