Despite the lack of differential methylation, many genes in A-1 were found to be significantly differentially expressed (such as BAX, E2F1, FADD, GADD45A, PRKCA and TP53BP2 of the p53 signaling pathway) indicating that DNA methylation is probably not the key epigenetic regulator for these genes in breast tumors. This evidence concerns the gene GADD45A and breast neoplasm.