Currently, a number of single-nucleotide polymorphisms (SNPs) in several genes and chromosome regions, such as ACE2, TMPRSS2, HLA alleles, and locus 3p21.31, have been identified to be associated with the susceptibility and outcome of COVID-19 by GWAS and exome sequencing as recently reviewed by Anastassopoulou et al. and Brest et al. [10, 11]. This evidence concerns the gene ACE2 and COVID-19.