BST2 and breast cancer: The expression level of BST2 protein was also increased in bone metastatic breast cancer cell line, MB-231BO compared to the normal breast cell line, MCF-10A and non-bone metastatic breast cancer cell lines, HTB-121, UACC812, MCF-7, T47D, MDA-468, BC-701 and MDA-231 by Western blot assay (Figure 3).