Therefore, the current study aimed to investigate if the DNA methylation levels of the ACE2 promoter are different depending on the genotype of five COVID-19-related polymorphisms: ACE2 rs2285666 and rs2074192, TMPRSS2 rs12329760 and rs2070788, and ACE1 rs1799752. The gene discussed is TMPRSS2; the disease is COVID-19.