xCT plays a key role in breast cancer progression, particularly in metastatic dissemination, since the exported glutamate, by activating the metabotropic glutamate receptor 3, induces the Rab27-mediated expression of the matrix metalloproteinase MT1-MMP on the cell surface, which degrades the extracellular matrix, favoring invasion [6]. This evidence concerns the gene SLC7A11 and breast carcinoma.