As we found high levels of XIAP 3′UTR were strongly associated with increasing capacity of metastasis in breast cancer, more and more evidence indicates that promotion of epithelial-mesenchymal transition (EMT), which refers to the transformation of epithelial cells from a well-differentiated phenotype to an invasive mesenchymal phenotype under pathological conditions [22]. The gene discussed is XIAP; the disease is breast carcinoma.