Regarding the DNA/RNA correlations, 44 out of the 44 (100%) tumors with DNA loss showed mRNA underexpression; however, 23 out of the 24 (96%) tumors with DNA gain and 172 out of the 179 (96%) tumors with “normal” DNA copy number also showed underexpression, suggesting that ECRG4 loss is not the main mechanism of underexpression in breast cancer. Here, ECRG4 is linked to breast cancer.