A small population of apparently normal breast epithelial cells could harbor BRCA1 promoter methylation in patients' samples with BRCA1-methylated tumors [41, 42], but not in those with BRCA1-unmethylated tumors. BRCA1 promoter was methylated in both normal and cancer breast tissue specimens of 11 patients which was statistically significant (p < 0.001), while 20 cases showed combined unmethylation of BRCA1 promoter. This evidence concerns the gene BRCA1 and cancer.