BST2, also known as bone marrow stromal antigen 2, is involved in the growth and development of B-cells. BST2 is a human cellular protein which inhibits retrovirus infection by preventing the diffusion of virus particles after budding from infected cells. Initially discovered as an inhibitor to HIV-1 infection in the absence of Vpu, tetherin has also been shown to inhibit the release of other viruses such as the Lassa and Marburg virions. Also, this protein may play a role in B-cell activation in rheumatoid arthritis. Recombinant human BST2 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography. Synonyms: Bone marrow stromal antigen 2, HM1.24 antigen, Tetherin, CD317. NCBI no.: NP_004326