ACE2 and COVID-19: Li et al., 2022, wrote a detailed review on the role of ACE2 and TMPRSS2 mutation and polymorphism in COVID-19 susceptibility and disease progression; following an analysis of 33 studies, 10 SNPs and 21 mutations in the ACE2 gene, as well as 13 SNPs and 12 variants in the TMPRSS2 gene, were potentially linked to COVID-19 [15].