Some DNA repair genes such as BRCA1 and PALB2 show relatively weak correlations between mRNA and DM (BRCA1, −0.32; PALB2, −0.40: Supplementary Table S3) and are thus not listed in Table 3; however, they may be regulated by promoter methylation in sub-populations of breast tumours. This evidence concerns the gene PALB2 and breast neoplasm.