Experimental analyses of breast cancer-specific biomarkers revealed the aberrant methylation status of seven genes (BRCA1, DAPK1, MSH2, CDKN2A, PGR, PRKCDBP, RANKL) that have an eminent effect on MTS spreading, making them perspective prognostic markers for breast cancer relapse risk [27]. This evidence concerns the gene PGR and breast carcinoma.