The alanine, serine and cysteine selective transporter 2 (ASCT2) receptor of syncytin 1 was furthermore expressed in endothelial and cancer cells [130,132,133,134,135], allowing a demonstrated fusion between breast cancer cells and endothelial cells that can be inhibited by syncytin inhibitory peptides [130]. Here, ERVW-1 is linked to breast carcinoma.