Table 1.

Epigenetic regulation of human ACE2 gene in different cell types/tissues

Cell type/Tissue	Epigenetic mark	Effect on ACE expression	Reference
Airway epithelial cells	Decreased DNA methylation of CpG (cg085599149) near the ACE2 transcription start site (TSS200 region)	Increased ACE2 expression	[31,32]
Lung tissue/Elder/Smoker	Hypomethylation of ACE2 gene	Increased ACE2 expression	[24]
Lung tissue (E096)	Histone modifications (H3K4me1, H3K4me3, H3K27Ac) in ACE2 gene	Increased ACE2 expression	[22]
Lung tissue (E096)	Upregulation of NAD-dependent histone deacetylase Sirtuin 1 (SIRT1)	Increased ACE2 expression	[22]
Lung/Children	Hypermethylation of ACE2 gene	Low ACE2 expression	[24,25]
Lung tissue/Systemic Lupus Erythematosus (SLE)	Decreased DNA methylation of ACE2 promoter (hypomethylation)	Increased ACE2 expression	[23]
Uterine Corpus Endometrial carcinoma	Decreased DNA methylation of ACE2 promoter (hypomethylation)	Increased ACE2 expression	[26]
Breast carcinoma	Increased KDM5B histone demethylase	Increased ACE2 expression	[22]
Kidney Renal Papillary Cell Carcinoma	Decreased DNA methylation of ACE2 promoter (hypomethylation)	Increased ACE2 expression	[26]