To support these observations, it is known that the ACE2 (locus Xp22.2) is located on the X-chromosome, and according to Gemmati et al. (2020), the X-linked heterozygous alleles could give females a significant advantage and a greater sexual dimorphism in counteracting viral infection and less severe manifestation of respiratory events as seen during COVID-19 pandemic in comparison to their male counterparts (Gemmati et al., 2020). This evidence concerns the gene ACE2 and viral infectious disease.