Similarly, Wang et al. used single-cell sequencing technology to evaluate the distribution and characteristics of ACE2 expression in testicular tissues of adult men, and found that ACE2 was specifically expressed in spermatogonia, Sertoli cells, and Leydig cells, suggesting that viral infection may cause disturbances in the biological function of the testes and abnormal spermatogenesis in males (Wang and Xu, 2020). Here, ACE2 is linked to viral infectious disease.