In summary, our results demonstrate that increased expression of NgBR in tamoxifen-resistant breast cancer cells promotes EGF signaling by increasing phosphorylation of AKT/ERK and MDM2, which attenuates the expression of p53 and increases the expression of survivin, which may lead to acquired resistance to tamoxifen as shown in Fig. 8. This evidence concerns the gene MDM2 and breast carcinoma.