Fig. 1.

Methylation frequencies of the tumor-suppressor genes in cancerous tissues and their corresponding normal tissues from the patients with breast cancer. (A) Methylation frequency of the 24 analyzed cancer-related gene regions in cancerous breast tissues. (B) Methylation frequency of the 24 analyzed cancer-related gene regions in the corresponding normal breast tissues. Numbers above each bar indicate the frequency of samples that were methylated in that region. The RASSF1 promoter was the most frequently methylated in cancerous tissues, and CDKN2B was the most frequently methylated in normal tissues. There were some gene regions whose methylation was not associated with breast tumor development (e.g., CD44, CHFR, and PTEN in tumors).