CD44 variant isoform 4 (CD44v4) is a major glycoprotein decorated with CD15s moieties in metastatic MDA-MB-231 cells [7], whilst more recent research from Shirure et al., using protease treatment, proved that glycosphingolipid CD15s in breast cancer cells is the E-selectin ligand, and there is the potential this could be targeted to prevent metastasis [5]. This evidence concerns the gene SELE and breast cancer.