Comparing the expression of TMPRSS2 and ACE2 reveals their overlaps and differences across human tissues and demographics. Both genes are coexpressed in respiratory and intestinal cells, and their overall expression levels are largely similar across sexes. However, their primary expression sites differ significantly: TMPRSS2 is expressed most highly in the prostate and more than ACE2 in the lungs, whereas ACE2 is most highly expressed in the testes.