Again, TCGA data analyses confirmed our results by indicating a frequent hypermethylation in primary tumor tissue and, accordingly, demonstrated an inverse correlation (r = –0.548, P<0.001) of NDRG2 methylation and mRNA expression indicating promoter hypermethylation as the molecular cause of the NDRG2 loss particularly in luminal and HER2-enriched breast cancer. This evidence concerns the gene ERBB2 and neoplasm.