To select a breast cancer cell line to study the role of NDRG4 silencing, we performed an expression meta-analysis in 51 human breast cancer cell lines25 using the GOBO application.26 Approximately one-quarter of the cell lines expressed a high level of NDRG4; we did not observe significant associations between NDRG4 expression levels and clinical (data not shown) or histological subgroups (represented by different colors in Fig. 4a). This evidence concerns the gene NDRG4 and breast carcinoma.