ACE2 and viral infectious disease: Moreover, the expression of ACE2 in spermatocytes, spermatids, and Sertoli cells enables SARS-CoV-2 infection in patients’ testes,89–91 leading to many uncertainties about the safety of male gametes and the risk of sexual virus transmission after SARS-CoV-2 infection.92 Taken together, the wide expression of ACE2 and high affinity between ACE2 and SARS-CoV-2 RBD provide high potential for SARS-CoV-2 viral infection in various tissues, and thorough studies with reliable data are therefore required.