Table 1.

Summary of rDNA methylation in selected cancer cases.

Disease	rDNA region	Methylation status	References
Late-stage ovarian cancer	18S and 28S rDNA	Hypermethylation	Chan et al. [38]
Breast cancer	18S, 5.8S, and 28S rDNA	Hypermethylation	Yan et al. [39]
Primary endometrial carcinoma	5.8S and 28S rDNA	Hypermethylation	Powell et al. [40]
Liver cancer	IGS	Hypomethylation	Zhang et al. [30]
Lung cancer
Prostate cancer
Colon cancer
Cervical cancer (cervical intraepithelial neoplasia (CIN))	Promoter	Hypomethylation	Zhou et al. [31]
Hepatocellular carcinomas	Promoter	Hypomethylation	Ghoshal et al. [2]
Primary oral squamous cell carcinoma (OSCC)	Promoter	No significant difference between cancer patients and control samples	Ha et al. [45]
Prostate cancer	Promoter	DNA methylation level remained unchanged	Uemura et al. [15]