Although the attributes of BST-2 that orchestrate its tumorigenic behavior1, 2, 3, 4 are not well understood, the tumorigenic functions of BST-2 in mouse models of breast cancer are consistent with human clinical data.3 Various cellular mechanisms, including, cell to cell adhesion, anchorage-independent growth, migration and invasion have been associated with BST-2-mediated promotion of cancer.1, 2, 3, 4. Here, BST2 is linked to breast cancer.