Importantly,for the infection to occur, the target cell must have both ACE2 and TMPRSS2 in proximity.Interestingly, TMPRSS2 is an androgen-regulated gene predominantly expressed in the prostateand with lower levels of expression in the lung, colon, liver, kidneys, and pancreas.Although most of TMPRSS2 is membrane-bound, it has also been identified in extracellularvesicles (25), suggesting that the protease canreach out tissues beyond its expression sites. This evidence concerns the gene TMPRSS2 and infection.