By analyzing 17 CP, 4 AP, 9 BC and 5 control (healthy donor) samples (mononuclear cells from peripheral blood or bone marrow) using the Reduced Representation Bisulfite Sequencing (RRBS) technique, Heller et al. [44] identified approximately 6500 differentially methylated CpG sites in the BC samples compared with controls. Here, CP is linked to breast cancer.