HEYL and COVID-19: Collectively, HeyL promoter in Egyptian population either COVID-19 patients or control healthy subjects was hypomethylated compared to the reference sequence published in GenBank (full methylated); however, partial methylated HeyL promoters containing methylated cytosine either CPG or non-CpG in Egyptian COVID-19 patients were more frequent than in control healthy subjects who showed more unmethylated ones as shown in Figure 3.