Strain specific BST2 expression analysis in homozygous B-hBST2 mice by flow cytometry. Spleen were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hBST2 mice (H/H), and analyzed by flow cytometry with species-specific anti-BST2 antibody. Mouse BST2 was detectable in wild-type mice. Human BST2 was exclusively detectable in homozygous B-hBST2 mice but not in wild-type mice.