Henarejos-Castillo I, Sebastian-Leon P, Devesa-Peiro A, et al. - Researchers investigated the susceptibility of the endometrium to infection by—and thereby potential damage from—SARS-CoV-2 via performing an analysis of SARS-Cov-2 infection-related gene expression from endometrial transcriptomic data sets. They obtained gene expression data from five studies in 112 patients with normal endometrium obtained throughout the menstrual cycle. Observations revealed high gene expression for TMPRSS4, CTSL, CTSB, FURIN, MX1, and BSG; medium for TMPRSS2; and low for ACE2. Increase in ACE2, TMPRSS4, CTSB, CTSL, and MX1 expression was observed toward the window of implantation. ACE2 and TMPRSS2 expression suggest that endometrial tissue is probably safe from SARS-CoV-2 cell entry, but a rise in susceptibility was observed with age. In addition, TMPRSS4, along with BSG-mediated viral entry into cells, could suggest a susceptible environment for SARS-CoV-2 entry via diverse mechanisms.