The present study provides methylation levels for the promoters of APC, BRCA1, CDKN2A, ESR1, ESR2, HER2/neu and PTEN, CDKN2A exon 2 and LINE-1 in tumor, tumor-adjacent and tumor-distant tissues from 18 breast cancer patients and normal breast tissues from four healthy women. This evidence concerns the gene PTEN and breast cancer.