Assessment by this MSRE-PCR assay of the same 25 BC samples that at the previous step underwent XmaI-RRBS analysis resulted in positive methylation calling from PRR5, PTGIS, ATOH1, CNIH3 and negative methylation calling from SNAP25 in all samples, an artifact that may be expected with the transition to another technology. This evidence concerns the gene PTGIS and breast cancer.