Despite the fact that a small proportion of spermatogonial stem cells express ACE2 and TMPRSS2, finding cells which co-express both genes is extremely rare, and scRNAseq data results suggest that spermatozoa may not be susceptible to virus infection owing to the lack of ACE2 and TMPRSS2 co-expression. This evidence concerns the gene TMPRSS2 and viral infectious disease.