ACE2 and COVID-19: This study did not find an association between the methylation levels of the ACE2 promoter and the genotypes of five COVID-19-associated polymorphisms (e.g., ACE2 rs2285666 and rs2074192, TMPRSS2 rs12329760 and rs2070788, ACE1 rs1799752) in individuals who had been previously hospitalized due to COVID-19 during the first wave of the pandemic and experiencing post-COVID symptoms.