From a genetic viewpoint, several single studies have investigated the association of different single nucleotide polymorphisms (SNPs) of ACE1 (e.g., rs1799752), ACE2 (e.g., rs2285666), or TMPRSS2 (e.g., rs12329760) genes with the severity of COVID-19 [4,5,6]. This evidence concerns the gene ACE2 and COVID-19.