Bioinformatic analysis of data obtained from Sanger sequencing of HeyL promoter in COVID-19 patients and control subjects helped us to evaluate the methylation status of target sequence including methylated cytosine either CpG (mCpG) or non-CpG (mC) as well as the location of methylated cytosine within HeyL promoter in comparison to the reference sequence published in GenBank under the accession number (Primary (citable) accession number: Q9NQ87, Secondary accession number(s): Q5TG99, Homo sapiens chromosome 1, GRCH38.P13, cover region: 39623435-39639643, Entrez gene ID: 26508) [13]. Here, HEYL is linked to COVID-19.